A Part Of Me Is Missing

I feel lost and confused. I think this is my own fault but still, I have forgotten how to be a child. I am thirteen years old and I frown on my piers. I don't think I am higher thatn anyof them but I look a them and their sense of humor and I feel like its not them who are stupid, its me who is a little too grown up. I used to think that I was just really smart, but then I read a book (it was a long time ago, and I don't remember the tittle) about a girl who's country was in a civil war. The class did a worksheet at the end and we concluded that the girl was forced to grow up and be mature. Now I am not comparing myself to a girl in a civil war but later I read about a boy who's father was a migrant worker, and the bot was uprooted constantly, therefore the boy was to act like a man. This was something I could partiallly relate to. I have moved around a lot in my life and I think that maybe it has had its effects on me. Well what I do know for sure is thea I feel a part of me is missing. I feel like I should be a little more athletic or something. I don't seem like a geek compared to other kids but when I talk its like we speak different languages. Like when I took a quiz with my girlfriend to find the ages of our inner children, her is 6 years old and mine is 45.