Well, here are some:

* parachuting from an airplane in flight.
* holding a "black cat" firecracker in my fingers when it went off.
* rappelling down a 150-foot-high cliff using clothesline and no harness.
* being in the Infantry.
* standing behind a plywood door while my brother shoots it with .22 caliber homemade wax blanks.
* having my leg sliced open with a corn knife.
* playing "In Between" with a hatchet.
* mixing ammonia and chlorine bleach to see what happens.
* being on unemployment.