Falling out of the second story of my window when I was younger, landing on my head. (Lucky me I landed on a bunch of rocks that spread out the force of impact, but still landed me in the hospital for a few days.)
Tripped down the (wooden)stairs of the apartment I stayed at, loose piece of wood jousted itself into my leg.
Funny part was, it only hurt for a second, and there was a hole in my jeans. Suddenly I couldn't walk right. After a half hour of prying at the hole in my jeans to see what it was and trying to ignore it, I found the chunk of wood.
The only part that really hurt was getting it taken out, it was about a foot long. Looking back, I suppose I'm lucky I can walk.