I think that probably hits the nail on the head-- the teachers. I *never* experienced the stereotypical mean kids picking on people or the beatdown thing, nor ever saw it happen to anyone else. Maybe the kids at my school were all supernaturally nice, but it's more likely I just had teachers who were good at keeping things in hand.

And, come to think of it, it was the same school and the same gym teacher from K through 6, so I really only had to get lucky the one time. :)