I was in a lift recently and held the door open for someone (who was clearly in a rush) just as it was closing, he'd asked if I was going to the ground floor, which I had intended to do but pressed the wrong button and ended up going two floors up the way. As soon as the doors opened he sprinted out, not noticing that he was on the wrong floor. Having realised that I'd fucked up I tried to close the door as quickly as possible, only he figured out his mistake before I got the chance and came back into the lift, gave me the evil eyes and we then enjoyed what had to be the most tense elevator ride either of us had ever experienced.
From now on I ain't holding the elevator door for anyone, this be my lift.