-You insult your siblings in Latin, and get away with it, because your parents have no idea what you said.
-You made togas for your Barbies.
-Mention of the Spartans is bound to provoke a negative reaction. Anyone who praises them is clearly an enemy of democracy. TRAITORS!
-You can actually pronounce the names "Gaius Julius Caesar" and "Pompeius Magnus" correctly *and* are able to give a recap of why they turned from friends to enemies.
-When in the voting booth, you write in the name Gracchi. You then complain because you think your tribe should have voted before all the other people standing in line.
-You feel the need to conquer new lands, merely to add another descriptor to your name. Africanus, anyone?
-You compare your significant other to one of your ancient heroes, and find them lacking.
-When you say "It's all Greek to me" it means you completely understand something.
-You drop Latin phrases into essays, casual conversations...and drunken texts/phone calls.