Oh, i got one... the people that feel it necessary to ALWAYS use the wheels on their suitcase whenever they are walking more than about 6 inches, and spend their whole time pulling the handle out and pushing it back in again.
Wheels it up to ticket barrier... stops pushes handle in, picks up... goes through barrier... stops, pulls handle out, puts down... wheels to the train... stops pushes handle in, picks up... gets on train... stops, pulls handle out, puts down... wheels to seat.... AAAAAHHH!