Drunk people are irritating. Don't be Aunt Mildred. Shut up already. There's nothing worse than someone trying to talk to you when you're trying to read. If the passenger beside you simply nods and looks back to her book, she's not feeling chatty and neither should you.
Mother says share.
There's nothing worse than an armrest hog. Quiet please, mom's sleeping. They won't like me very much if they wake me up. Chew with your mouth closed. There's nothing more grotesque than poor table manners, even if it is only airplane food.