My father in law is suffering from dementia. As a result, he often cannot remember even very important events a few hours after they occurred. For now, at least, he can still remember a ton of detail about events that happened 60, 70, or even almost 80 years ago.
When my kids were very small, I was a bit disappointed to realize that when they were older they would forget all about most of the stuff that we had done together before they were five or six years old. At least, it has been my experience that most folks can't remember much before age 5. I used to wonder if that cutoff age would move higher as I aged. So far, it doesn't seem to be the case. I may have lost a few stories or details from the 5 and 6 year old era of my life, but I don't think I remember it much differently than I did when I was 26 instead of 56.
Sometimes intense emotions seem to promote better retention. For example, my brother chopped a slice in my scalp with a metal toy hoe when we were both quite small. In that case, however, I'm not so sure that it made such an impression on me as it did on my mother who often told the story. In fact, I'm really not sure whether I remember the event or her account of the story.
On the other hand, I distinctly remember taking a card and a tin of home made cookies to a 5 year old friend whose appendix had just been removed. I was 5 myself and had no idea what an appendix was or how one would have it removed. Adults seemed reluctant to discuss the specifics. However, being sent to a neighboring apartment with cookies in hand made it very clear that this was a momentus occasion. I visited briefly with the friend, but he seemed a bit lethargic and his parents discouraged active play. So I was glad to scarf a cookie or two and split.
I also remember hanging out at the apartment house playground with the same little buddy. A very early memory is one of us swinging gently side by side as we each lay on a swing on our stomach. We were discussing something that I can only remember as being intensely intellectual in the judgment of 5 year olds. My friend's mother called for him. We purposed to ignore her and continue our conversation. Eventually we were found and he was hauled off to dinner or a bath or some such incidental matter. The magic moment was disturbed. We were unable to come to a conclusion in our deliberations.
As I write these stories, I realize that dozens of others are springing into my conciousness. The pact to eat berries to test their poison content. Sliding down the side of a freshly painted building in my favorite tassled suede cowboy jacket, thus destroying it. Pulling up handfuls of coarse grass and realizing that it had cut my hands. Popping up at a window and awakening a sleeping baby repeatedly so that the mom had to keep coming back into the nursery to see what was wrong. Burning my fingers as my mother wisely allowed me to play with matches while she supervised.
I am having a pretty good time now with my earliest memories. I hope you get a chance to visit yours soon!