I was just reminiscing on something that happened when I was in second grade.

I was sitting on a stationary bike while watching T.V. The room I was in used to be the garage, but it had carpet put down over the concrete (The crappy flat kind that's usually put down at schools or businesses.) . Anyways, somehow I got the bright idea to start rocking the bike from side to side. It was fun at first, but the fun died quickly when it began to actually FALL OVER. I managed to jump off before it landed, however, I did not land on my feet. I ended up having to wear a cast for several months because of my idiocy.

What's the dumbest thing you've ever done? Feel free to answer this question in the comments section of this post.