No one remembers the
womb.
No one remembers
birth.
No one remembers their
first breath of air.
Of course, some people don't remember five minutes ago, but the point I'm getting at is that there's a period in the beginning of one's life that's simply not recorded, consciously at least. A period where our
experiences and
environments shape our
personality, but we
remember nothing of. I've seen photos, tons of them, of powerful and important experiences I had as a young child, but without the pictures I'd have no idea that it ever happened. It lasts different lengths for everyone, but on average it's over by time you're 5 or 6 years old. Of course, the shroud isn't complete. Everyone has hazy isolated memories, there being more the older you were when they occurred.
I suspect that this all correlates to the development of
consciousness somehow, but that's just my whacky theory.