I was on a houseboat in Tennessee for the 4th of July with my friends and my brother. It was late at night, we were all drunk, and my brother and I decided to go swimming. Instead of immediately jumping in, I climbed down the ladder to avoid waking everyone up. As I submerged into the water, my brother thought it would be funny to drop the ladder on my head.
The ladders on that boat were big, metal, and very heavy.
I was unconscious, floating around under the boat for 10 seconds, then swam back up. When I got back up, instead of yelling and beating the stuff out of my dumb-forget brother, we had a few shots and went fishing.