Another powerful technique is the "link method":
- Take the items to be memorized (like a series of numbers).
- Transform each one into an image.
- Create a scene or story linking the image.
- To recall, simply follow the chain of images.
For example, to memorize a shopping list with milk, eggs, and butter:
- Picture a giant milk carton.
- Imagine the milk carton opening, and a dozen eggs spilling out.
- The eggs crack open, and gallons of melted butter come pouring out.
By vividly linking images together, vast amounts of mundane data can be made unforgettable in creative ways, allowing mental athletes to perform staggering feats of memorization like reciting thousands of digits of pi.
Section: 1, Chapter: 4
In Chapter 10, Foer profiles Daniel Tammet, a British savant who can recite over 22,000 digits of pi from memory, learn Icelandic in a week, and do complex arithmetic in his head. Tammet attributes his abilities to an unusual brain condition combining synesthesia (where senses are linked, i.e. numbers have colors and emotions) with Asperger syndrome (a form of autism). His feats of memory supposedly come automatically due to his unique neurology.
But as Foer investigates Tammet's background, inconsistencies emerge. Tammet had previously competed in the World Memory Championships using standard memory techniques under a different name. His descriptions of synesthetic experiences change suspiciously in retellings. Certain feats are replicated by non-savant "mental calculators" using simple mnemonic systems.
While Foer falls short of accusing Tammet of fraud, he suggests his extraordinary abilities may be more learned than innate - not so different from "normal" mental athletes who train their memories.
Section: 1, Chapter: 10
In contrast to S's incredible memory, consider the story of EP, a man with one of the most severe cases of amnesia ever documented. After a bout with herpes simplex encephalitis, EP was left with extensive damage to his hippocampus and medial temporal lobes, wiping out his ability to form new long-term memories. Trapped in an eternal present, EP is a profound case study in the importance of memory to identity, relationships, and one's ability to function in the world.
Tying into EP's story, Foer makes the point that our sense of time and our very identities are structured by our memories of events. The more memories we create, the more "chronological landmarks" we build into our mental model of the past, helping us organize our experience. People with Alzheimer's and severe memory loss don't just lose their pasts - they lose their ability to imagine the future too.
This insight suggests an actionable lesson we can all apply: Be mindful about creating lots of memorable experiences in your life. Seek out new adventures, visit new places, learn new things.
Section: 1, Chapter: 3
the 19th century, mnemonic techniques enjoyed a brief popular resurgence not as learning tools, but as performance. Traveling "professors" of memory would put on stage shows demonstrating seemingly superhuman memorization and calculation abilities.
One of the most famous, Alphonse Loisette (real name Marcus Dwight Larrowe), charged exorbitant sums for his memory training courses and was as celebrated as he was controversial. Even Mark Twain fell under his tutelage for a time, though he would later come to regret his association with the huckster.
Figures like Loisette represented a "vulgarization" of the classical art of memory, turning it into little more than a vaudeville act. But while serious interest in mnemonics waned, these performers unintentionally kept the ancient techniques alive until their academic and practical value could be rediscovered in the late 20th century.
Section: 1, Chapter: 6
Foer describes his struggles to memorize his first poem using the techniques of the memory palace. He breaks the process down into steps:
- Choose a memory palace with a clear spatial layout you know well, like your childhood home.
- Read a line or short stanza of the poem, and create a memorable mental image capturing its meaning and sound.
- Place the image in a specific location along your memory palace route.
- Move on to the next line, creating a new image and placing it in the next locus.
- To recall the poem, retrace your route through the palace, using the images you placed as cues to reconstruct the lines.
The key is translating the abstract words into concrete, spatially located scenes. With practice poems can be committed to heart with ease - an invaluable skill in the ancient world before books were common.
Section: 1, Chapter: 5
Chapter 1 introduces the story of a Russian journalist named S who showed up at psychologist A.R. Luria's office in 1928 claiming to have an abnormally powerful memory. Luria studied S for 30 years and wrote a book about him, finding S's memory was virtually limitless. However, S was crippled by his inability to forget anything. His mind was constantly cluttered with trivial details and sensations.
While S's memory was seemingly sui generis, Foer suggests it may be possible for anyone to attain similar memorization abilities through training. He cites a study comparing the brains of mental athletes to a control group that found no neuroanatomical differences - only that the mental athletes were engaging different brain regions related to spatial memory and navigation. This suggests their skills were achieved through practice rather than innate ability.
Section: 1, Chapter: 1
Is it really possible to have a "photographic memory" like the famous savant S, automatically recording everything you see and hear in perfect detail? Foer argues the answer, with one notable exception, is no. The one credible case of photographic memory comes from "Elizabeth," a Harvard student studied in the 1970s who could fuse two images in her mind into a mental composite. He concludes that true photographic memory is at best exceedingly rare, and possibly nothing more than an urban legend.
If savants aren't relying on innate photographic memory, how do they perform such remarkable mental feats? Brain scans of savants like the famous Kim Peek (the inspiration for Rain Man) show unusual patterns of damage, especially to the left hemisphere, along with hyper-connectivity in other areas. This suggests savants' abilities may emerge from unique constraints that force their brains to operate differently, not inborn superiority. Foer argues this is also how memory techniques seem to work - by consciously constraining our minds to encode information in more memorable ways, while screening out distractions and irrelevant stimuli. The lesson is that incredible memory isn't just for savants.
Section: 1, Chapter: 10
Foer lays out the basic technique for memorizing used by mental athletes: the "memory palace." Invented in ancient Greece, this powerful method exploits our brain's natural spatial memory abilities. To use it:
- Visualize a familiar physical space, like the layout of your house.
- Mentally place the items you want to memorize throughout the rooms, creating an associative link between each item and a specific location.
- To recall, simply retrace your steps through the memory palace. The distinctive items and images you placed will spring back to mind.
By tying information we want to remember to places and images, we take advantage of how the human brain evolved to work - not as a filing cabinet for abstract symbols, but as a way of navigating the world and remembering what's important. Even the most mundane facts can be made memorable with enough creativity in transforming them into strange, lewd, funny, or bizarre mental images and scenes.
Section: 1, Chapter: 4
Chapter 9 introduces the story of Raemon Matthews, a high school teacher in the South Bronx who uses memory techniques to help his disadvantaged students succeed. Matthews teaches at the Samuel Gompers Vocational High School, where many students come from poverty and score well below average on standardized tests.
But the group of students Matthews coaches for the memory competition, known as the "Talented Tenth," regularly win honors and go on to top colleges. The key, Matthews argues, is combining memory training with high expectations. By drilling his students on memorizing facts and figures from their textbooks using visualization and the memory palace technique, he gives them a tangible way to master academic content.
Even more important are the lessons in discipline, organization, and self-belief. By showing students they can overcome mental limitations to achieve seemingly impossible feats, Matthews convinces them they have what it takes to succeed no matter their background. Memory training instills an attitude of accomplishment that carries over to all their studies.
Section: 1, Chapter: 9
Today we live in a world of ubiquitous external memory. Books, recordings, photographs, and digital databases have made memorization effectively obsolete for most practical purposes. With smartphones and the internet, we have instant access to more information than the greatest scholars of antiquity could ever dream of. But Foer argues this comes at a cost. By outsourcing our memories to external devices, we risk diminishing our own capacity to think and engage with knowledge. We become ever more dependent on our machines, passive consumers of information rather than active rememberers and thinkers.
The solution, Foer believes, is to cultivate memory as an act of intellectual resistance in an age of forgetfulness. Even if the art of memory isn't strictly necessary today, practicing it develops our capacity for concentration, creative thinking, and deep engagement with knowledge. It keeps us cognitively fit and independent even as technology promises to do our thinking for us.
Section: 1, Chapter: 7
In the ancient world, before books were common, orators would use the method of loci to prepare for speeches. The Roman rhetorician Cicero was said to practice by memorizing the physical locations of his speeches, placing the topics he planned to discuss into the courtrooms, auditoriums, and amphitheaters where he would be speaking.
This allowed him to deliver long, complex addresses without notes, moving from point to point in his mind as he moved from place to place in the physical location. Using associative imagery allowed him to speak naturally and fluidly, without pausing to consciously recall the next set of facts from rote memory.
Section: 1, Chapter: 4
Chapter 6 traces the long history of memory training and how its role in Western civilization has changed over time. In the ancient world, before cheap writing materials were available, enormous value was placed on committing knowledge to memory. Orators like Cicero would memorize hours-long speeches, poets would recite epic stories passed down for generations, and scholars would memorize entire books.
Well into the Middle Ages memory skills were considered a core part of education and high culture. But with Gutenberg's invention of the printing press, books became more widespread, and the value placed on memorization gradually declined. By the 19th century, rote learning in schools was increasingly criticized as stifling to creativity.
The Romantics valued inspiration and emotion over meticulous learning. As books became cheaper, the great traditions of memory training faded into obscurity. Only in our own time, with the pioneering work of a few iconoclasts, have the ancient techniques been systematically revived.
Section: 1, Chapter: 6
The success of Raemon Matthews' students raises important questions about education. In an age of smartphones and Wikipedia, factual knowledge can seem obsolete - memorization dismissed as an archaic relic.
But cognitive scientists make a convincing case that memory is the foundation of higher thinking skills. You can't analyze what you don't know. Critical thinking depends on a rich body of memorized facts and concepts that can be fluently retrieved and combined. But many students today suffer from shockingly sparse mental models of history, science, art, and culture - crippling disadvantages in an innovation economy.
Foer argues memorization and critical thinking aren't opposites but two sides of a well-rounded mind. Just "knowing how to think" isn't enough - you need something to think about. By bringing memory training techniques into the classroom, teachers can help students quickly build the background knowledge they need to engage with complex ideas.
Section: 1, Chapter: 9
In the climax of his year-long memory quest, Foer competes in the USA Memory Championship in New York City. Up against experienced mental athletes, Foer is a clear underdog, but his training pays off in a stunning upset. In the first event, memorizing the names of 99 strangers' faces, Foer comes in third, beating out dozens of more experienced competitors. But it's his performance in the next event, "speed cards," where he really shines.
Using the mnemonic "person-action-object" system, he was able to memorize the order of a shuffled deck of cards in just over a minute and a half - a new US record. As the day goes on, Foer continues to hold his own against the field, advancing to the final round against former champion Ram Kolli. In the ultimate showdown, a trial to see who can memorize the most from a double deck of cards, Foer emerges victorious. The former journalist had become the new US memory champion, proving just how far dedication and smart training techniques can take you.
Section: 1, Chapter: 11
While researching memory techniques, Foer discovered an unexpected benefit beyond just memorization skill: Forcing his brain to operate differently changed the very way he perceived and processed new information in his daily life.
As he practiced visualizing information spatially and associatively rather than just verbally and linearly, his whole way of thinking shifted. Poetry became richer and more evocative as he pictured the scenes described vividly in his mind. Conversations became more memorable as he automatically noted interesting imagery and analogies. Even his appreciation of art took on new dimensions as he immersed in the details of paintings and sculptures.
Memory training, he realized, doesn't just allow us to memorize facts - it can reshape our entire way of processing the world.
Section: 1, Chapter: 4
Since prospective memory is so flaky, the author provides some practical tips for overcoming this all-too-common weakness:
- Write it down. Put the task on your to-do list, calendar or phone.
- Make specific plans with salient cues. Vague intentions like "I'll exercise sometime today" rarely happen. But "I'll go for a run in the park at noon" is more likely to stick.
- Use visual cuing. Want to remember to take the cookies to the party? Put them on top of your car keys so you can't miss them when it's time to go.
- Set alarms/reminders, especially if your routine is disrupted.
Section: 2, Chapter: 9
Chapter 15 details the complex effects of stress on memory formation and retrieval.
- Acute stress causes release of hormones epinephrine and cortisol, which signal the amygdala to activate the hippocampus to consolidate the stressful event as a memory. This prioritizes storage of important, survival-relevant information.
- An optimal amount of acute stress improves attention and memory formation. Too little stress and consolidation isn't boosted.
- Chronic stress leads to prolonged cortisol release, impairing the hippocampus and its ability to form new memories. It can even cause hippocampal neurons to wither and die.
- Techniques like meditation, exercise, yoga and reframing negative thoughts can reduce perceived stress and protect the brain from its memory-harming effects.
Section: 3, Chapter: 15
Chapter 10 dives into the unavoidable fading of memories over time, a phenomenon first scientifically studied by Hermann Ebbinghaus in the 1800s. His famous "forgetting curve" shows that memory loss happens rapidly at first, then tapers off, with about 25% of the original material retained in the long run if there's no further review.
This forgetting occurs because the neural connections housing the memory physically decay if not reactivated. However, some residual trace remains - relearning forgotten material goes faster than the first time, a "savings" effect.
To combat time's memory-eroding effects, repeated retrieval of the memory is key, preferably spaced out over time vs. crammed. Overlearning, continuing to study even after you can accurately recall it, also helps cement long-term retention.
Section: 2, Chapter: 10
The author offers tips for avoiding or quickly resolving the awkward social gaffes caused by forgetting names:
- Pay attention when first hearing the name. Many name lapses aren't true forgetting but rather a failure to encode the name initially due to distraction or disinterest.
- Repeat the name aloud: "Nice to meet you, Sarah." Hearing your own voice say it boosts encoding.
- Make the name meaningful. Sarah > has red hair like your sister Sarah, sell seashells by the seashore, dated Sam in high school, etc. Attach personal, visual or memory palace-style associations.
Section: 2, Chapter: 8
Sleep is one of the most important factors for forming and retaining memories for the long term:
- During sleep, the brain replays and strengthens neural connections that were active during learning. This aids consolidation of new memories.
- Lack of sleep impairs attention the next day, making it harder to encode new memories. It also prevents the full benefits of rehearsal and practice from taking hold.
- Naps can boost memory as well. A 20-minute nap after learning something new can provide significant memory enhancement without the grogginess of longer naps.
- Most importantly, chronic sleep deprivation is a major risk factor for Alzheimer's. During deep sleep, the brain clears out the amyloid protein that can lead to dementia.
Section: 3, Chapter: 16
Chapter 3 covers working memory - the temporary, limited memory store for the present moment.
- Working memory only holds what you're paying attention to right now, for about 15-30 seconds. It's constantly updated as events unfold moment to moment.
- Visual working memory is like a "mental scratchpad" and auditory working memory is like a brief "mental soundtrack" or "echo".
- Working memory has a small capacity, able to hold only about 7 ± 2 "chunks" of information at a time. Chunking information into meaningful units can expand how much you can fit in working memory.
- Important information can be plucked from working memory and consolidated into long-term memory via the hippocampus if it captures your attention. The rest is quickly forgotten as working memory updates.
Section: 1, Chapter: 3
Semantic memory is our memory for facts, the "Wikipedia of your brain". Semantic memories are facts you know without remembering how you learned them, like the capital of France or your birthdate
Acquiring semantic memories requires effortful studying and repetition, ideally spaced out over time vs. crammed. Self-testing is even better than restudying for strengthening semantic memory
Attaching meaning, like with mnemonics (Every Good Boy Deserves Fudge for music notes) or a personal association (Laird Hamilton the surfer is married to volleyball player Gabrielle Reece) makes facts stickier Using visual-spatial memory techniques like memory palaces can drastically improve recall of lists and strings of information in order
Section: 1, Chapter: 5
Paying attention is crucial for memory formation. Some key insights:
- You can only remember what you pay attention to. Perception alone isn't enough - you must add your attention to encode something into memory.
- Attention acts like a "save button", capturing certain details to be consolidated while the rest is discarded and forgotten. What you pay attention to depends on what you find interesting, meaningful, surprising, emotional, etc.
- Distractions, stress, lack of sleep and excessive screen time all impair attention and memory. To remember more, practice mindfulness, get enough sleep, and limit distractions.
- If you forget something, like where you parked, it's often due to lack of attention, not a memory failure. You never encoded the parking spot in the first place.
Section: 1, Chapter: 2
Chapter 11 explores how forgetting isn't always a passive, uncontrolled process - we can actively choose to forget things we don't want to retain, though it's not always easy. Unwanted thoughts and memories can be intentionally suppressed by redirecting attention whenever they come to mind, depriving them of the rehearsal needed to solidify long-term storage.
In many everyday situations, some strategic forgetting is beneficial. Truly traumatic, intrusive memories are much harder to shake, but working with a therapist to reframe them into less devastating terms during reconsolidation may lessen their sting. Memory and forgetting have a yin-yang relationship - both are essential for a healthy, well-functioning mind.
Section: 2, Chapter: 11
How memories are made:
- Memories are formed through lasting physical changes in the brain in response to experiences. The process involves four steps:
- Encoding - translating sensory information into neurological language,
- Consolidation - linking related neural activity into a connected pattern,
- Storage - maintaining the neural pattern over time through structural changes,
- Retrieval - reactivating the stored neural pattern to recall the memory.
- The hippocampus is essential for consolidating new consciously retrievable memories by binding together disparate neural activity.
Section: 1, Chapter: 1
That frustrating feeling of blanking on a word or name you're sure you know is called a "tip of the tongue" (TOT) experience. It occurs when there's only partial activation between the concept you're searching for and it's name/label.
- It happens to all ages but increases after age 40 due to slower neural processing. TOT becomes more noticeable and worrisome to older adults.
- Proper names are the most common targets of TOT because, unless meaningful to you, they lack semantic associations in the brain (the "Baker/baker paradox")
- Cues like seeing/hearing the first letter or number of syllables sometimes slip through during TOT. An "ugly sister" - a similar-ish but wrong word - may also come to mind
Section: 2, Chapter: 8
The capacity of working memory was found to be 7 ± 2 "chunks" of information by researcher George Miller in 1956. A chunk is a meaningful unit of information. Some examples:
- Phone numbers are 10 digits but are chunked into 3 pieces (area code, first 3 digits, last 4 digits), allowing them to fit in working memory
- 12062007 is harder to hold in working memory than 12/06/2007, which chunks the numbers into a memorable date
- The letters "ALMNVYESIGIANEAOSM" exceed working memory capacity, but the same letters chunked as "MY NAME IS LISA GENOVA" are easy to retain
Section: 1, Chapter: 3
The difference between memory for facts and events vs. memory for skills:
- Declarative memories are consciously recalled facts (semantic memory) and personal experiences (episodic memory). They feel effortful to retrieve and are easy to forget.
- Non-declarative "muscle memories" are unconscious memories for how to perform learned motor skills (typing, bike-riding, playing an instrument, etc). They are automatic and durable, but take a lot of repetition to acquire.
- Muscle memories rely on the basal ganglia and cerebellum to consolidate, not the hippocampus, so they were spared in famous amnesic patient HM who could form new skill memories but no new declarative memories after his hippocampus was removed.
- Both types of long-term memory formation require attention and practice, but muscle memory mastery takes much more repetition than factual or event memory.
Section: 1, Chapter: 4
Chapter 18 presents a philosophical perspective on the importance of memory, acknowledging both its centrality and its flaws. The healthiest approach is to hold memory as both "everything and nothing."
- On one hand, our memories make us who we are, allowing us to learn, grow, and connect with others. Valuing memory motivates us to keep it sharp and treasure the meaningful moments.
- On the other hand, putting too much stake in memory sets us up for disappointment, since it is inevitably imperfect, changeable and prone to distortion. Even the best memory sometimes fails.
- A balanced view is to take memory seriously but hold it lightly. Use tools to improve and preserve it but accept its inherent limitations. Don't catastrophize when it fails.
Section: 3, Chapter: 18
Episodic memories, though often vividly recalled, are highly prone to distortion and inaccuracy. Episodic memories are incomplete from the start because we only encode select details.
During consolidation, memories are frequently edited with elaborations, reinterpretations and flat-out fabrications filled in unconsciously. Memories change a bit each time we recall them based on our current mood, knowledge and beliefs. The altered version overwrites the original in a process called reconsolidation.
In studies, people have been easily manipulated to recall detailed memories of getting lost in a mall, spilling punch on a bride, and seeing footage of 9/11 planes crashing that doesn't actually exist
Section: 2, Chapter: 7
Prospective memory - remembering what you need to do later. It relies on external cues (time-based like a 2pm meeting or event-based like buying milk when you see the store) to trigger recall of the intended action. It has two components:
- forming the initial intention and
- retrieving it at the right time. Failure is common in both steps.
It's more of a "forgetting" system than a memory system. Up to 70% of daily memory lapses are prospective memory failures. Prospective memory declines with age but is also error-prone in youth, with 50% of 20-somethings forgetting to do an action just 2 hours later in one study
Section: 2, Chapter: 9
Consider these examples of how even people with extraordinary memory abilities still forget and make mistakes, illustrating memory's imperfections:
- Akira Haraguchi, who memorized over 100,000 digits of pi, still forgot his wife's birthday.
- Legendary cellist Yo-Yo Ma once left his priceless cello in a New York City taxi.
- World memory champion Joshua Foer, who can memorize a deck of cards in under 2 minutes, admits these techniques don't make him immune to forgetting why he walked into a room.
- These anecdotes demonstrate that even the most exceptional memories aren't infallible or all-encompassing. Mistakes and lapses can happen to anyone - it's only human.
Section: 3, Chapter: 18
The author highlights how meaning and emotion influence what our brains choose to remember or let fade away:
- Meaningful memories are stickier than neutral ones. We forget most of life's routine details (what we ate for lunch last Tuesday) but remember meaningful or emotional events (a great trip) for years.
- Attaching personal significance to information makes it easier to learn and retain.
- Mnemonics work because they make nonsense meaningful.
- Memories linked to strong emotions like fear, joy, grief, or love are more vivid and long-lasting, even if details drift over time.
- Memory has a "positivity bias," preferentially storing and recalling positive memories and associations over negative ones to maintain our rosy self-image.
Section: 2, Chapter: 10
Since we forget the vast majority of our life experiences over time, the author offers some tips for retaining more autobiographical memories:
- Keep a journal - this not only preserves details of your day, but the act of writing aids consolidation and the journal can provide retrieval cues
- Take photos/videos - looking back on these media later helps you relive experiences and retain them longer
- Reflect and reminisce - thinking and talking about memories reactivates them, making them more durable
Section: 1, Chapter: 6
We don't remember most of what happens to us, only retaining select fragments of our personal past. Autobiographical memory is the story of your life stitched together from your most meaningful episodic memories. It's highly selective and forms the basis of your identity.
We tend to remember events that are emotional, surprising, personally significant, and self-relevant. The mundane and routine rarely make the cut. Repetition and rehearsal, like retelling stories or looking at photos, strengthens autobiographical memories, but also makes them vulnerable to distortion over time. Each recall modifies the memory.
There is a "reminiscence bump" between ages 15-30 when many of our most vividly remembered autobiographical events occur - likely because of all the memorable "firsts" in those years.
Section: 1, Chapter: 6
The author shares the example of celebrated cellist Yo-Yo Ma accidentally leaving his priceless cello in the trunk of a NYC taxi cab. Even for something as important as a $2.5 million instrument, working memory is still fragile. Ma likely forgot the cello because, in his rush, the cello case wasn't in his field of view when he got out of the cab, so there was no visual cue to trigger his working memory to retrieve the cello. This shows how critical cues and context are for memory retrieval. Without them, even the most important things can be forgotten in the heat of the moment.
Section: 1, Chapter: 3
The author shares a relatable example of walking into her kitchen for her reading glasses, only to instantly forget why she went there. She looked around for cues to jog her memory, but the context of the kitchen provided no relevant clues, so she remained stumped until returning to her bedroom. There, surrounded by the cues present when she first had the thought to get her glasses, like her book on the nightstand, she instantly remembered her glasses again. This illustrates how memory relies heavily on context - we remember best when the context at retrieval matches the context at encoding.
Section: 1, Chapter: 2
Memory retrieval depends heavily on context - the external environment and internal state present when a memory was formed.
Memories are easier to recall when the context at retrieval matches the context at encoding. This applies to place, time, people, and even internal states like mood, hunger or caffeine levels. Conversely, being in a different context than where you learned something can impair recall.
To leverage this, study under conditions similar to the test. Drink coffee while studying and testing. Recall what you learned in the same room. Context matters!
Section: 3, Chapter: 14
Books about Memory
Memory
Psychology
Learning
Personal Development
Moonwalking with Einstein Book Summary
Joshua Foer
Joshua Foer chronicles his journey from covering the U.S. Memory Championship as a journalist to becoming a competitor and ultimately winning the event himself, all while exploring the history, science, and techniques of memory training and the untapped potential of the human mind.
Memory
Psychology
Neuroscience
Personal Development
Remember Book Summary
Lisa Genova
In "Remember", neuroscientist Lisa Genova explores the intricacies of how we create, retain, and retrieve memories, offering fascinating insights and practical strategies to harness the power of your memory while accepting its inevitable imperfections.
