The Sixth Finger
I was driving my teenage daughter and her friends to the mall and, playing off a tangent in their conversation, told them that I had had six fingers on one hand for the longest time because my dad couldn't afford the operation.
I said one night my dad made me drink a full bottle of whiskey then we went and lay that extra finger across the train tracks and wham! Come the next train it came right off.
One girl gasped and said "really?" and I said "hell no." Made me happy.
Coda: I had been the best damned passer in the football league until that digit was removed. I have never been any good since. Many, many interceptions.