I've got this quirk. Whenever I type something that I type often -- say, a username and password -- I will pull back my right hand when done and drum my fingers across my desk. It's very odd and I've only recently become aware that I'm doing it.
I mean, I've always been aware, but I've only recently noticed that I always do it and always in these circumstances. Any time I've typed something rote and reach back for my mouse, I tap the fingers. It's like knocking on wood or something.