Why are the girls in my graduating class so stupid?

They all went around telling everyone to overdress on Friday for our last day of school... right? well i was ok with that, so i did, and then when i got to school only half the people who told other people to dress up were dressed up? wow.. that's cool. now i feel like i should be at the prom instead of taking exams... and it kind of makes me super angry.. XD