I learned at 6, had training wheels for a day before my father decided I was ready to do without... too early I think. Man, I crashed a lot, many scabs. My girlfriend dug a little rock out of the back of my knee a couple years ago (23 now) and it looks a lot like the kind of grey crushed rock they used to put on the roads around my community at that time. Probably came from one of those "mom! don't touch it! no I don't want you to clean it out! I don't care! nooo!" times that I probably should have let her.