I don't think people tend to believe me, but I remember learning how to walk. There was a fairly short area of our house between two corners, and I distinctly remember that standing in the corners was generally easy -- I had two places to put my hands and old myself. The corner provided quite a bit of stability. But, walking in between the two corners was quite difficult because I only had one wall within to balance myself. I would confidently stand in the corner, and walk to the next corner somewhat quickly and awkwardly to minimize the amount of time I had to maintain my balance.

When I was very young, I was somewhat neglected, and also quite introverted. As a result, I spent a lot of time by myself, thinking and introspecting. I don't remember if I realized this myself, or if someone taught it to me -- but at some point perhaps age 5-9, I was aware that memories were not permanent, and drifted over time. I spent a lot of time thinking, and trying to remember the clear facts of my earliest memories, and do my best to commit the the discrete facts of my memory to what I considered my "permanent" memory. I was distressed by the idea of degradation and loss, and so the idea of making permanent memories was especially appealing. I vaguely recall selecting three different memories for "permanence," but I only remember one clearly. The 2nd one I remember vaguely, and it's generally too crude and embarrassing to bring up when discussing these sorts of topics. (it was about diaper changing) The "learning to walk" memory is the one I bring up the most, and is the most interesting, since it can be roughly dated. I was just a bit over a year old. I don't recall the possibly third memory whatsoever.

People will tell you that revisiting a memory is the same as "rebuilding" a memory, and therefore that you're modifying the memory in an unconscious way every time you do this. I disagree somewhat: you have partial control over how much a memory drifts. You can declare the facts (in the case above: the corners, learning to walk, and how precarious my walking was between the corners) firmly an indefinitely. It's only the the less important details that drift. What color were the walls? Was there carpet? Which house was I in when I made this memory. Not only can I not answer any of those questions, but I'm fairly confident that the hallway I "remember" forming this memory in is not the hallway it actually occurred in. The hallway I remember wasn't available to me until I was about 3 years old, or so. And so, it is possible to compare facts and introspect in at least some cases and attempt to correct the record. I would also argue that introspection itself is a skillset which exists on its own bell curve. Are of aware of what facts you know vs. which you don't? Do you have a sense for which memories you can be certain of? How well do you know your own thoughts and motivations? Like any mental skillset, these are things at which people can be worse or better.

Lastly, I would note that that you do retain all sorts of things which might be called memories from youth: how to articulate your hands. How to see silhouettes, how to move your mouth in order to make the correct sounds. These aren't things you have visual memories, but these are things your brain learned to do at a young age, and has never forgotten. Certainly, these patterns have been reinforced this whole time, which must help significantly. By replaying my memory of learning how to walk, I have done the same: reinforced it over decades, so that it could survive into my 40s, where it otherwise would have been permanently lost. If I had the foresight to reinforce other memories, who knows what else I could remember.