I've also wondered how much abuse affected my sexuality.

In the earliest memory you mentioned, you were exposing yourself to a 4 year old. How old were you? How did you feel about doing that?

I remember being at my best friend's house, we were maybe 6-8, and she was trying to talk the 4 year old boy next door into showing us his privates. I was so embarrassed!

Maybe you just have a high libido and are just horny. There's nothing wrong with that. I wouldn't call it hyper sexual... Just horny.