Resizing and decapping (.30 Herrett, I think) with the TV on. Upstroke of ram, left thumb in the way. Like has been mentioned, compound leverage! Caught between the case mouth and the bottom of the die, the decapping pin ran right through my thumbnail. Missed the bone and poked out through the other side!
It hurt!
So, natural reaction was to jerk the hand away from the press. Hadn't really realized yet what had happened and hadn't lowered ram, so the case mouth and decapping pin still had the thumb trapped.
It hurt more!