MicShazam

When we were young, me and my brother ran through these patches of very tall dry grass of some sort at a beach. They were the height of a person, so we jumped through them, ran to the next one, jumped through, etc. Then suddenly, my brother stopped running, but I jumped through the next one anyway. I landed in a small stream of water on the other side, my head right next to a big rock. Pretty dumb and pretty lucky.

Also, a long time ago in France, I ran down a hill very fast and all of a sudden I realized the hill stopped and turned into a straight drop. I fell almost 2 meters straight down and landed on my knees on a gravel path. Ouch.

EDIT: I forgot one more. Some years ago, on a yearly family weekend, we were some uncles, aunts and cousins playing this game outside in the dark at night. Basically, someone is "it" and has to find everyone else in the dark. There's a spot where if you run up to it and shout "I'm free" before you're spotted, you avoid being "it" in the next round. The one who was looking for where we were hiding was walking away from where I was hiding, so I dashed fast across the lawn about 15 meters, not remembering that there was a tiled fireplace in the middle of the lawn. I couldn't see anything as the lawn was just pitch black. I landed on concrete tiles with my knees, having run at full speed. I don't know why I keep demolishing my knees.
If that sounds like an unresponsibly dangerous game, it should be said that you're supposed to do it in daylight, but we used to do it at night because drunk uncles, stupid ideas, etc.