Something you know you do differently than most people.
Amanda says I deal from the bottom of a deck of cards, not from the top.... I didn't know that was different from other people until she mentioned it. :-)
I also pour the cream before the coffee... most people I know pour the coffee in first and then the cream. :-)
I can't make it through a movie without critiquing on the style or historical accuracy of the costumes and planning to make a re-make of at least one gown in the film. I suppose other historical costumers do that, but not most people in general. :-)
What about you? Did I miss anything? ;-)