Knock, knock.
Who's there?
Shhhhhhhhhh.
Shhhhhhhhhh who?
Shhhhhhhhhhampoo!
Knock, knock.
Who's there?
Shhhhhhhhhh.
Shhhhhhhhhh who?
Shhhhhhhhhhampoo!
Listen up, buttercup. This is a play on words. The person at the door says "Shhhhhhhhhh," and you're supposed to ask, "Shhhhhhhhhh who?" which sounds like "shampoo." Shampoo is something you use to wash your hair, which I'm sure you're familiar with since hygiene is a new thing for you, isn't it?