OMG Gary you've opened a massive can of worms here.
Pet peeve, waiting in a queue at the tender station, when some smart @ss thinks they can come in from the side simply because the came down a different set of stairs or just stepped off the lift/elevator.
People pushing my daughter out the way at the buffet bar, do they honestly think the food is going to run out.
Why oh why are people so rude these days.