system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Even if we can't access them, do all memories remain stored in the brain throughout life?

I mean every single sight we've ever seen, every emotion we've felt and at what time, the links between the two, all of it. I'd really like the answer to be yes, so that one day, if technology reaches that point in my lifetime, I'll be able to relive it all in some way.
gpt
No. Although we know that some memories exist but are difficult to access, we also know that memories can fade away.  This seems to be particularly true for memories that aren't accessed often.  
  
In fact, studies show that when a memory is accessed, it is virtually "wiped away", but then re-stored.  This seems to strengthen the memory again, but there's a downside. Each time we do this, the memory can be disrupted. It can be changed. We can end up "remembering" things that are very different than what actually occurred.   
  
So when you access an old memory, you aren't really dredging up the original events that you stored away in your brain. You are remembering the memory of a memory of a memory....