When I was a little kid my brother (who's older) used to play D&D with the two boys across the street and I used to go watch them. They didn't want me to play for various reasons (the most obvious being that I was probably annoying) but they always warded me off by showing me that it said right on the box and the books "For ages 10 and up".
Guess what *I* insisted on doing on my 10th birthday?
So I joined their campaign and we played for YEARS. When I was in middle school I started developing my own game universe and everything and in high school I ran my own campaigns. I haven't tabletopped since college, now. I'm sure there's many ways to play D&D online nowadays, I just don't have time.