If you happen to think Halloween is October's most important holiday, think again. Ever since the iconic line, "It's October 3rd" was uttered by a fresh-faced Lindsay Lohan in Mean Girls, that fateful date has been universally recognized as "Mean Girls Day". Even Lindsay Lohan decided to acknowledge the holiday by posting a series of Mean Girl-related Instagrams, including one in which to a possible sequel to the cult teen comedy called Mean Moms. "I'm trying to make it happen," she wrote. Now the question is, how are YOU celebrating Mean Girls Day?