40 years ago, some idiotic teenaged boy was showing off, ran up behind me, picked me up from behind then dropped me so that when I landed, I dislocated my kneecap.  5 years ago, an idiotic custodian wasn't thinking, mopped our school elevator during the school day (not overnight like he is supposed to do), left no warning cones up, and I slipped on the wet floor injuring my back and the same knee.  A few months after that, we were in Provincetown, Cape Cod at their only chain grocery store.  Their ice machine was leaking and had a huge puddle in front of it that, of course, I didn't see because there was no "wet floor" cone up.  Once again, I fell hurting the same knee.  Last December, arthritis in my bad knee finally got the best of me, and I ended up with a burst Baker's cyst and a torn meniscus from doing absolutely nothing except getting older.
I injured my shoulder at work 30 years ago catching a falling disabled woman and trying to prevent her from hitting the ground.  I should have let her fall.  Now the arthritis in it bothers me all the time.
Getting old is rough on the accident-prone.