Yep I'm with you on that. One time I was going over a song with one of the sections(Squimish Sopranos, on the piano). I hit the middle G and it would not sound. I looked inside and hit the key again. That time two strings flung out and engraved themselves in my arm. One went in about to the bone and the other I had to pluck out. There was blood everywhere. Because it was a pretty clean cut it wasn't too painful. It was actually the screaming panic of about 10 screaming sopranos that did me in. Also there was a time I was tuning a guitar(and not paying attention to the tension), one of the strings snapped and hit me in the eye. I recovered from both incidences but still have scars. Oh, and I've been hit in the head with a nylon tipped drum stick. It was being flung at me from a stage 20ft away. That REALLY hurt. There was also this time I hit myself in the face. I was really into the song... I fell backwards and got a little stuck. (The drum set was in a kitty corner adjacent to a wall of chimes and other forms of percussion.
Instruments like hurting me.