The first memory I have was when I was in Kindergarden so I was probably five. It was recess and we were playing in the playground. This playground had some sort of platform that you could hide below. So Carlos, who might have been my best friend at the time, led a bunch of other boys under this platform and subsequently unzipped his pants and revealed his penis. Then he laughed and ran away. I think we all laughed too. I really don't think I'm the same person then. First of all, I would never follow someone underneath a playground, and if someone showed me his penis, I would probably kick it real hard or run away. I definitely would not laugh. I think this was an extraordinary circumstance and made it very memorable.
I find it interesting that many of the earliest memories people remember is from around 2-4, but yours and mine were from a slightly older age of 5-6 and that we both consider ourselves different from the "us" in our earliest memory.