Airplane etiquette is critical. Have you ever been about to fall asleep on a plane when someone does this? It’s obnoxious. Being jarred violently is bad enough, but sometimes they catch your hair too. It’s got to be due to a lack of awareness, but come on. On a plane, you’re locked in a cramped assigned seat in a giant metal tube in the air. There’s no reasonable way to vent your frustration other than to give a dirty look. Be a good guy and push yourself up off your armrests.