How old were you when you realized...

That most adults are actually really stupid. About 12.

When I took a chemistry class in college I realized I wasn’t very smart. Age 19.

That people who think they’re smart are usually quite dim and that people who think they’re average or dim are usually smart. Age 25 or so with hints in that direction in my teens.

i was 5 when I realized that I had been alive for 5 years.

I was seven when I realized I was born completely naked. I remember being pretty disturbed by that new information.