The Library Season 3, Episode 5

Elaine

Well, she didn't ask me what I wanted.

Secretary

She must have forgot.

Elaine

How could she forget I've been ordering lunch every day here for 3 and a half years?

Secretary

I don't know anything.

Elaine

Ah, you don't know anything. You see, 'I don't know anything', means there's something to know. If you really didn't know anything you would have said 'You're crazy.'