My earliest memory is 2ish, being gurneyed from a hallway with my mom (clearlyu upset) into the surgical area before my first open heart surgery. The memory faded over time, until it became a memory of a memory around age 45...I can tell there was a change from remembering detail, like anything about the wheeled bed, to the base characteristics of the memory.

My Mom didn't tell me the story, nor could she have described the moment, as she doesn't remember. I remember. On the other hand, I do remember that my primary cardiac surgeon, Dr. Rosengart, was not part of the entourage of staff wheeling me in. I met Rosengart again when I had my last open heart surgery at age 31.

It's uncommon for people to have memories from age 2, but I've met quite a few people with early memories, as it can be a fun topic to discuss. Parents try to anchor kids first memories as happy, but my anecdata doesn't seem to fit a pattern of trauma or banal or happy. Early fixed memories seem utterly random.

I've wondered whether one can train a child to remember things by recalling things that happened to them repeatedly, but I guess it will create such an induction. And they don't even have language to understand "Remember Monday, 2 days ago, grandma visited.".

And perhaps under a certain age, the brain really has no programming to store anything as memories...

There’s nuance here. I think I experienced the same thing maybe not quite as young but I distinctly recall the crib I was in as well as the day I got upgraded to a regular bed. Along with that I remember specific objects that I had around me which were later confirmed by my parents’ photos.

There a potential selection bias in the criminal witness example which is capturing adult memories that may be less sticky than those from an early age. That could explain some differences there.