Truer Words Have Never Been Spoken

I just overheard a conversation between an undergraduate student and her grandfather:

Grandfather: "You are becoming a drunk."

Granddaughter-Living-Large-on-Someone's-Dime-at-a-Nearby-Private-University: "I am not a drunk! I just like to drink a lot."

How do you argue with logic like that? I bet she is pre-law.