I broke my scaphoid 4 years ago in an unfortunate dodgeball accident.  It's a little kidney shaped bone in your hand kind of at the base of your thumb.  Main way to break it is falling over backwards and trying to catch yourself(don't do that).  Took a month to find, had to do an MRI.  I can still feel it now as I am typing, just kind of a dull pain.  One surgery to put a screw in, then the screw worked out and another surgery to take it out.  Very painful injury.  Lost the dodgeball game, by the way...