I didn't you plum. The knock knock joke is what Peter Kaye did first!
Knock knock
Who's there?
Biggish
Biggish who?
No thanks mate.
Big Issue Page 2
It's the same joke, different set-up.
Doctor, Doctor. I've got a strawberry in my head. Doctor replies, "Lets put some cream on it then.
So I went to the chemist with this strawberry in my head, they said, "We better get you to a doctor." "No" I replied "I just want some cream for it."