I was jumping on a trampoline and feeling pretty good from landing some moves I was working on. I did a back hand spring, and bounced a few times back and forth gaining momentum. Then a front flip - pretty soon, I felt invulnerable. Maybe it was the release from all the fear and frustration of not getting my moves, or if it was the bliss of being in the air, but I felt invincible. Then, with momentum carrying me upon landing, I ricocheted off the trampoline and banged my heel on the steel base of a vault. The fall must have only been 3-4 feet max, but ouch. Funny how quickly invulnerability fades when you realize how fragile the human body is.