Number one pet peeve when I travel : People who constantly open the window when almost all the passengers are asleep. I mean, what in the world are you trying to see there? Can they be more considerate? Ooohhh, that really annoys me!
This is one of my pet peeves, too. When the cabin is pitch black and it's obvious people are sleeping and someone opens a window, lighting the whole cabin and keeping it that way. Their need to see is more important than the 100+ other people who want to sleep. Drives me crazy.