Can human memory ‘fill up’?

We all have core memories — maybe it’s a first kiss, the birth of a child, a favorite meal you’ve had. If you’re like most people, you probably also remember some things you’ll never have reason to use again — an old phone number, the combination to a locker you used a decade ago.

But do you ever worry that your brain will run out of space? That you’ll lose the ability to make new memories?

On the one hand, yes, the brain is finite. There are only so many electrons and chemicals available. But it is also very clever and agile at eliminating things that are less meaningful to us, so there’s no chance you could ever truly run out of space as you age, like you might on a computer.

The brain is designed to get rid of things that are not critically important. This is useful for our survival, actually — you can’t store all the information you process, so your brain can retain a piece of information for a few seconds, then get rid of it.

But this also means that the brain has the ability to retain things that are vital to you. Think about your parents, for example. Your memories of them likely are very textured and diverse. You have verbal memories of them, you may remember certain facial expressions they made, maybe even how they smelled. The more memories you have of a specific person or experience means that they are stored in multiple places in your brain.

You also have certain things stored as motor memories — things your brain no longer has to consciously process but has held on to. The classic example is riding a bike. Once the skill is developed, your brain stores it like a rock.

There are some areas of the brain that due to genetics can be better developed in some people. Think of people born with fabulous motor memory — someone who is a concert pianist at a young age. Others have greater capacity in the visual part of the brain, those with so-called photographic memories. It’s important to remember, though, that because the brain is finite, there may be other areas where these people have less capacity — the ability to make judgments, for example. Everyone has different talents.

So don’t think of it as the possibility that your brain will “fill up.” Keep in mind that there is always room for new memories, and your brain is genetically engineered to retain the most important ones.