Well, skipping over bits which might not be appropriate for a "family-friendly" board, I've been hit in the head with a steel horseshoe, the full weight of a 12' or so 2x8 (on the narrow edge), and a concrete step, I've broken bones and set them myself, had a few skate tumbles...and the things which were even more painful sound really lame. One was a time I woke up with a kink in my spine that refused to crack no matter how I tried, and just got steadily worse. I was pretty pale and clammy for hours from the pain of that, and spent most of my work shift lying flat on the floor. The other is migraines I sometimes get.