I like to joke with my wife that her antics, like taking the chalk away from the table, would get her thumbs broken anywhere but in our basement. Last night I was playing and tapped the ball with my practice swing, and then took a quick stroke to make the shot... 
My wife assured me that this was a great way to get my thumbs broken..
It's just a joke in reference to The Hustler, but what other bad habits will get your proverbial thumbs broken?

My wife assured me that this was a great way to get my thumbs broken..
It's just a joke in reference to The Hustler, but what other bad habits will get your proverbial thumbs broken?