I know you are but what am I?
The most brain-dead comeback in the history of brain-dead comebacks. It’s like your brain is on vacation.
He said I was a donkey. I said, 'I know you are, but what am I?' and kept walking.
She said I was a joke. I said, 'I know you are, but what am I?' and laughed.
He said I was a mess. I said, 'I know you are, but what am I?' and cried.