What day is it? It's "Mean Girls" Day. A seemingly simple exchange from a movie that came out 15 years ago has become a full-fledged day of celebration every Oct. 3. In "Mean Girls," Lindsay Lohan’s character Cady Heron recounts a conversation with her crush, Aaron Samuels, played by Jonathan Bennett. He asks her what day it is, and she responds, "It's October 3rd." It was a moment that launched a 1,000 memes. So how do you celebrate "Mean Girls" Day? Wear pink and eat some cheese fries.