It's been 10 years since Cady joined the Plastics, and even though you don't have to deal with calculus anymore, adult life still has its share of cat fights and weird social rules.
Re-watching Mean Girls is more than just nostalgia for the struggles of high school and girl world. It might help you figure out the work world a little better too.
Take a mature look at the cult classic film and you may find that life isn't that different after high school. Except maybe prom wasn't as everything you ever hoped it would be.