Saltines.

I was working drive-thru as usual.

This guy comes through, and he ordered a salad.

I handed him all of his junk, but before I could slam the window on him, he inquires

"Do you have any crackers?"

I glanced away, wondering if he was serious.
He was.

"No, sir, we don't have any crackers."

He looked at me as if I was lying to him.

"Are you sure you don't have any?" He asked again.

I rolled my eyes slightly as I replied,

"Sir, the only cracker in here is me."

Needless to say, he stared at me blankly for a second before muttering a half-hearted "Thanks." And driving away.