Remember: The Science of Memory and the Art of Forgetting

by Lisa Genova

In fact, most of us will forget the majority of what we experience today by tomorrow. Added up, this means we actually don’t remember most of our lives.

Why do we remember our first kiss but not our tenth? What determines what we remember and what we forget? Memory is quite economical. In a nutshell, our brains have evolved to remember what is meaningful. They forget what isn’t. The truth is, much of our lives are habitual, routine, and inconsequential. We shower, brush our teeth, drink coffee, commute to work, do our jobs, eat lunch, commute home, eat dinner, watch TV, spend too much time on social media, and go to bed.

often forget not because it’s efficient for our brains to do so but because we haven’t supplied our brains with the kinds of input needed to support memory creation and retrieval.

You’ll learn that attention is essential for creating a memory for anything.

Without adding your attention, you never formed a memory for where you parked in the first place.

You’ll see how memory is profoundly impacted by meaning, emotion, sleep, stress, and context.

Memory is the sum of what we remember and what we forget, and there is an art and science to both. Will you forget what you experience and learn today by tomorrow, or will you remember the details and lessons of today decades from now? Either way, your memory is miraculously powerful, highly fallible, and doing its job.

Every memory you have is a result of a lasting physical alteration in your brain in response to what you experienced. You went from not knowing something to knowing something, from never before having experienced today to having lived another day. And to be able to remember tomorrow what happened today means that your brain has to change.

Creating a memory takes place in four basic steps: Encoding. Your brain captures the sights, sounds, information, emotion, and meaning of

what you perceived and paid attention to and translates all this into neurological language. Consolidation. Your brain links the previously unrelated collection of neural activity into a single pattern of associated connections. Storage.

Memory is different. When we remember something, we’re not withdrawing from a “memory bank.” There is no memory bank. Long-term memories don’t reside in one particular neighborhood in your brain.

If we want to remember something, above all else, we need to notice what is going on. Noticing requires two things: perception (seeing, hearing, smelling, feeling) and attention.

We tend to pay attention to—and therefore remember—what we find interesting, meaningful, new, surprising, significant, emotional, and consequential. Our brains capture those details. We ignore, and therefore forget, the rest.

Because we remember what we pay attention to, we might want to be mindful about what we focus on. Optimists pay attention to positive experiences, and so these events are consolidated into memory. If you’re depressed, you’re less likely to consolidate happy events or pleasant experiences into memory because happiness doesn’t jibe with your mood. You don’t even notice the sunnier moments when you’re only focusing on the dark clouds. You find what you look for. If you look for magic every day, if you pay attention to the moments of joy and awe, you can then capture these moments and consolidate them into memory. Over time, your life’s narrative will be populated with memories that make you smile.

Episodic is personal and always about the past.

Semantic memory is about information and is timeless.

Episodic memory, your memory for what happened in your life, is the history of you remembered by you.

Episodic memory is time-traveling to your past. Remember when…

unless I revisited the experience of that day by thinking about it and talking about it regularly, it is likely to be forgotten.

Life events infused with emotion are what we tend to remember long term—triumphs,

Emotion and surprise act like a big brass marching band parading through your brain, waking up your neural circuitry to what is going on. Routine events are never emotional or surprising. And because experiences that elicit an emotional reaction in you most likely also matter to you, you tend to revisit them.

Strung together, your most meaningful episodic memories create your life story and are collectively called your autobiographical memory. This is your highlights reel—your first kiss, the day you scored the winning goal to clinch the championship, the day you graduated from college, your wedding day, the day you moved into your first house, the time you got that big promotion, the births of your children. The meaningful moments you keep within the chapters of your autobiographical memory aren’t necessarily all tales of rainbows and unicorns. What you remember depends on the kind of life story you’re creating. We tend to save the memories that feed our identity and outlook.

In terms of what happened, we remember almost nothing before the age of three and very little before the age of six.

But most of life’s episodic memories are likely to be clustered between the ages of fifteen and thirty. Called the reminiscence bump, these episodes are what we remember most in life. Why is this? We don’t really know, but most scientists think it’s because so many meaningful firsts are packed into those years—kiss, love, car, college, sex, job, house, marriage, child. During these years, we begin to fill our life’s narrative with purpose and meaning. And again, our brains remember what is meaningful.

Your episodic memories are chock-full of distortions, additions, omissions, elaborations, confabulations, and other errors. Basically, your memories for what happened are wrong.

For every step in memory processing—encoding, consolidation, storage, and retrieval—your memory for what happened is vulnerable to editing and inaccuracies. To begin with, we can only introduce into the memory creation process what we notice and pay attention to in the first place. Since we can’t notice everything in every moment that unfolds before us, we only encode and later remember certain slices of what happened. These slices will contain only the details that were seduced by our biases and captured our interest.

In the process of consolidating an episodic memory, your brain is like a sticky-fingered, madcap chef. While it stirs together the ingredients of what you noticed for any particular memory, the recipe can change, often dramatically, with additions and subtractions supplied by imagination, opinion, or assumptions. The recipe can also be warped by a dream, something you read or heard, a movie, a photograph, an association, your emotional state, someone else’s memory, or even mere suggestion.

every time we retrieve a stored memory for what happened, it’s highly likely that we change the memory. As described earlier, when we retrieve a memory of something that happened, we are reconstructing the story, not playing the videotape. Memory isn’t a courtroom stenographer, reading back exactly what was said. When we recall what happened, we typically fetch only some of the details we stored. We omit bits, reinterpret parts, and distort others in light of new information, context, and perspective that are available now but weren’t back then. We frequently invent new information, often inaccurate, to fill in gaps in our memories so that the narrative feels more complete or pleasing. What we remember about the past is also influenced by how we feel in the present. Our opinions and emotional state today color what we remember from what happened last year. And so, in revisiting episodic memories, we often reshape them.

And then something interesting happens. We reconsolidate and restore this changed, 2.0 version of the memory and not the original. Reconsolidating an episodic memory is like hitting save in Microsoft Word. Any edits we’ve made are saved to the neural circuits of that memory. The earlier version of the memory that we just retrieved is now gone. Every time we recall an episodic memory, we overwrite it, and this new, updated edition is the version we’ll retrieve the next time we visit that memory.

Writing something down allows you to rehearse and therefore strengthen the memory for the details you choose to write about, but this action can also unwittingly prevent you from rehearsing, and therefore later remembering, any details you didn’t include.

Putting any sensory experience into words distorts and narrows the original memory of the experience. As a writer, I find this phenomenon more than a little disheartening.

even talking about your memory of what happened slices the memory thinner.

The spoken story of what happened is first narrowed by language’s limited capacity to describe the imagery, sounds, smells, feelings, and other impressions of any experience. And we cherry-pick only certain details when we describe what occurred.

After we talk about something that happened, this slimmer version of the memory is saved, and so we lose the fuller, original memory. Then, the next time we talk about this memory, maybe we leave out a detail. You don’t mention that it had been raining. When we go to retell what happened a third time, the rain is gone from the memory. So as soon as a...

The number one archenemy of the memories you’ve created and stored is time. It’s not enough to pay attention to an experience, pluck some pieces of sensory information and emotion from it, bind them together into a singular memory, and then store that memory through alterations in synaptic connections between the neurons that were originally activated by that experience. If you don’t revisit the memory, if it just sits on your brain’s cortical shelf like an old trophy collecting dust, that memory will erode with the passage of time.

memory is transient. It eventually fades.

But there is also evidence that memories can be physiologically erased. More recent studies have shown that if the collection of synapses representing a memory isn’t activated over time, the connections will be physically pruned away. If dormant for too long, neurons will literally retract their anatomical, electrochemical connections with other neurons. The connections, and consequently the memory contained in those connections, will no longer exist.

Paying attention is the number one thing you can do to improve your memory at any age, and a lack of attention will impair it. Every time.

While we can’t necessarily free ourselves from the stress in our lives, we can dramatically influence our brain’s and body’s response to each stressful situation we find ourselves in. Through yoga, meditation, a healthy diet, exercise, and practices in mindfulness, gratitude, and compassion, we can train ourselves to become less reactive, to put the brakes on the runaway stress response, to stay healthy in the face of toxic anxiety.

Only 2 percent of people with Alzheimer’s have the purely inherited, early-onset form of the disease. Ninety-eight percent of the time, Alzheimer’s is caused by a combination of the genes we inherited and how we live.