The Secret Power of Forgetting

“I am more forgetful these days. Is this normal for old age or am I getting dementia?“

I started my last post with this question and reflected on how attention intersects with our memory. We first need attention to record an event or fact into our memory.

Today, I want to focus on another aspect of this question. Assuming that we did record the memory, what makes us forget it?

Neuroscience has focused on the study of memory in detail over the last few decades, but studies on “forgetting,” its counterpart, have lagged somewhat. Case in point: A PubMed search on “memory” (June 17, 2026) returned more than 460,000 articles, whereas “forgetting” resulted in 16,000, about 3.5 percent.

But understanding the mechanisms of forgetting may be just as important as understanding memory itself.

Role of Forgetting

One of the more fundamental advances in understanding memory is that our memory is a dynamic phenomenon. We may even call it a reconstruction by our brain, rather than a passive recording of events.

This shift in perspective allows us, in turn, to understand that “forgetting” can also serve a purpose.

Forgetting isn't a failure of memory; it's a consequence of processes that allow our brains to prioritize information that helps us navigate and make sense of the world.

Imagine remembering every detail of every day with equal clarity. Every breakfast, every receipt, every conversation. Such a system would not be a gift but a burden. For efficiency, the brain must compress, summarize, and discard. Forgetting is not the enemy of memory. Forgetting increases behavioral flexibility and removes irrelevant information. It is similar to how decluttering our possessions can lead to a cleaner, more organized home.

Posttraumatic stress disorder (PTSD) and other mental health conditions can arise when memories trap us in recurring cycles of distress, intrusive thoughts, and unwanted impulses. Across traditions—from Buddhism to modern psychotherapy—many approaches to human suffering share a common theme: learning how to loosen the grip of memories, thoughts, and patterns that no longer serve us.

Then, forgetting is actually a powerful tool.

How do we forget? What is the art of forgetting?

It is hard to “forget” on will or command, just like it is hard to sleep on will or command.

Perhaps the key to understanding forgetting lies in understanding how we remember.

Secrets of Remembering

Of the many things we encounter each day, only a tiny fraction become memories.

Repetition tells the brain that information may be useful again.

Attention tells the brain what deserves a place in the archive. Memory is not merely a record of our lives. It is the residue of what we attended to.

This is why we can, at least partially, control and shape our memory. We can focus on what we want to attend to and repeat it. Over time, the unused memory will inevitably fade.

Emotion tells the brain that something matters. The hippocampus is very close to our emotion center, the amygdala. If there is a threat, we should remember not to repeat it. Fear and perhaps anger, shock, or disappointment help in this context.

One way to think about emotion is that it acts as a highlighter. It tells the brain, "This matters. Remember this."

But memory and emotion, while deeply connected, are not identical.

In an experiment with Alzheimer's patients who have lost their abilities to remember new things, subjects were divided into two groups. One watched a comedy and the other a sad movie. Afterward, subjects could not recall the plot of the movie, but the emotional effect lingered. Those who watched a sad film remained sadder, and those who watched a happy film remained happier, despite having little or no memory of why they felt that way.

Memory Essential Reads

Why We Screenshot Things We'll Never Look at Again

Are We Still Friends? The Importance of Memory Updating

Tying to emotion is the best way to remember things. That is why it is easier to remember our wedding day, or the moment our favorite sports team won the World Series, compared to what you ate for lunch on a mundane Tuesday. And when memory is associated with negative emotions, it is even harder to erase.

Neuroscience of Forgetting

Neuroscience is just starting to understand the mechanism underlying “forgetting.”

Neuroscientists once thought forgetting was simply the passive fading of memories over time. Increasingly, evidence suggests that in addition to the natural decay of passive forgetting, there is a biological process of “active forgetting” with molecular-level mechanisms, as well as system network-level mechanisms.

Specialized networks involved in storing memories, sometimes called engram cells, appear to be continuously remodeled throughout life. Sleep, new experiences, physical activity, and even the birth of new neurons may help the brain update old memories and make room for new ones.

Studies are also beginning to suggest that conditions such as anxiety, posttraumatic stress disorder, obsessive-compulsive disorder, and addiction may involve impairments in active forgetting.

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So how can we forget better?

We cannot simply command ourselves to forget. But we can influence what our brains strengthen and what they gradually release.

We can focus our attention on what matters: rehearsing the values, relationships, and goals we want to preserve.

We can practice letting go of small resentments and recurring conflicts.

We can protect sleep, exercise regularly, and create space for new experiences.

Most importantly, we can recognize that forgetting is not always failure. Sometimes it is healing.

Memory gives us continuity, but it is not a perfect record. It is selective, adaptive, and reconstructive. We are shaped not only by what we remember but also by what we forget.

In my previous post, I wrote that attention builds the archive. Forgetting edits it.

We become what we attend to. The converse may also be true: We are also shaped by what we stop attending to.

Forgetting does not merely erase the past. It frees us to move forward.