SA for me... Was probably at it's peak around 13 - 15. Or maybe because I was just highly immature back then. I'm not sure. But I'm 17! I feel too old now.
Don't feel intimidated by age though! We're all drawn here for the same cause and pretty much the same reason.
Haha, I'm 16. It's good that there are people my age on this site, but also sad because, well, we should be enjoying our teenage years with careless abandon.