I have no idea what my DS15 youngest memory is but it's not very young. I've tried talking to him about the preschool/daycare he attended and he has very little recall of it. To my surprise he doesn't recall a lot from 6th grade. My husband remembers very little from his youth (before 12 or 13) and I'm wondering if my DS is like this as well. I am sure if one could prove it somehow, that my husband retains a lot of what he learned at that age. Just not things he experienced. In my case i can remember certain moments vividly from the time I was 3, and I from around 5th grade on I remember a lot including details such as how classes were picked, why I took a certain extra-circular, those kids who teased me.