I was five years old when I had fantasies about the boys in my kindergarten class being naked and tied up with the ropes our teacher used to hang the class art from. I told such fantasies to another girl in my class and the face she made let me know this was the kind of thought I should keep to myself.
I was also five when I pestered my mother about where babies came from until she confirmed my suspicions about what exactly sex was. And then of course I wanted to go and try it and she freaked out...didn't get that opportunity for quite a few years after that, lol.
It's funny that I never thought that there was anything wrong with me, but I also didn't know that other people had such desires until I was in high school, and I didn't know such desires had names until the beautiful internet came along.