eli5: how is it that human doesnt remember anything from first several years of their life?


We took our now 3,5 years old son for a trip to USA last fall … so he was 2,5 years old that time. We live in Europe. Next week i am traveling there again so i spoke with him about me traveling to USA and he started asking me questions about places we were last year. Also he was telling me many specific memories from that trip last year and was asking me about specific people we have met. That is not surprising, it was last year. But how is it possible, that he will not remember anything from it 15 years from now if he remember it year after? I mean, he will not remember he was in USA at all.
I would understand that kids and toddlers keep forgetting stuff and thats why they will never remember them as an adults. But if they remember things from year or more ago, why will they forgett them as an adults?

In: 2567

Memory is a very complex thing, it’s not like a computer’s hard drive. Memory is connections between ideas. In the years children are in school we stuff their minds full of all sorts of ideas. This onrush of ideas causes reorganization of the ideas from before school, and some content is lost in that reorganization. Memory is not highly accurate, so content is lost all the time, but until that baseline of “stuff everybody knows” is loaded memories are particularly susceptible to loss during reorganization.

If you have a book that has just one page of text, you will likely remember quite well what happened in what part of that page. As you age, you gain massive amount of new experiences of all kinds. Suddenly you are sitting with a trilogy, with each book having thousand pages, and you are trying to remember what exactly happened on page 41 of the first one.

What I read suggests that some research supports the idea that the development of language plays an important part in memory.

I have one memory from when I was between 1-3 years old. I’m playing with a wheel loader toy on a tile table. That’s it.

It’s a very complex subject for an ELI5
As someone who studied neuroscience the reality is that we do not have all the answers to how the brain works, or even most of them.

Worth remembering there is a difference between memory and recall. Your son will have been impacted by the trip and he will remember this in actions and responses even if he thinks he can’t remember. As an example, i was chased by a dog when I was of similar age. I remember it happened but can’t recall any specifics of the event. It did, however, cause me to have a phobia of dogs well into my teenage years.

You could start a fun experiment by asking him to recall as much as he can about the trip, write it down, and repeat your test every 6 months. As an additional arm to the test, ask him details about something else he remembers from a similar time then don’t ask him about it again for a couple of years. Compare accuracy of follow-up responses.