i was 6 or 7 when i received my first scar.......it's at the corner of my left eye, we were throwing bricks and one caught me on the side of the head when gravity took over......
second major scar is a 5" #7 on the top of my head, caught it on the steel rod hook thing which keeps the top bunk together when i jumped headfirst into the bottom bunk.....had something like 100 stitches, i forgot all about it until i shaved my head for the first time years ago and saw it, chicks dig scars
he'll learn his balance, if he doesn't come around maybe see an ear specialist as my nephew had problems with balance until they figured out it was something in his ears, they did the tubes and he was fine, he was 4 or 5 iirc.