Back when I was in preschool, I discovered that if I put the back of one of those fisherprice plastic outdoor rocking horses on the edge of the elevated sidewalk, I could get it to jump really high. Well, long story short, I made it jump too high, and it slipped off the sidewalk, causing it to flip completely over, and I ended up splitting the back of my head open on the concrete. Still have a bald spot on the back of my head.