A disorder that follows watching the movie Mean Girls which causes one to quote said movie in everyday conversations (whether they make sense or not). It may also cause the person to intergrate Mean Girl quotes in other movies or event, such as the Hunger Games, or Harry Potter, or even the olympics.
Girl 1: "Oh, i wonder what this shirt is made out of, cotton?"
Girl 2; "Your mom's chest hair!"
Girl 1: "Oh, no you have mean girlitis too?"
Girl 1: "Ok, sandy you have four candy canes"
Girl 2: "Do i have any?"
Girl 1: "No, none for gretchen weiners"
Girl 3: "ignore her she has mean girlitis"