a laugh at my expense

So, tonight, under the influence of sugar, I was thinking how stupid the comeback

"I know I am, but what are you?!" is.

For example, someone says, "You are a moron!" and the proper response is: "I know I am, but what are YOU?!"

Then, Chris pointed out that its' actually "I know YOU are, but what am I?"

I'm thinking I am a moron. Or Blonde, or I guess they go hand in hand.