I know I am but what are you? - A funny way to make someone talk about themselves like they'

A funny way to make someone talk about themselves like they're a fool.

'I know I am but what are you?' I said. He said he was 'a philosopher' and then asked me if I had a sandwich.

'I know I am but what are you?' I asked. She said she was 'a queen' and then said she needed a crown.

'I know I am but what are you?' I said. He said he was 'a hero' and then ran away from a spider.