Knock knock. Who's there? Purpose.

Purpose who? That's what I've been asking myself for years.

Knock knock. Who's there? Wanda.

Wanda who? Wanda why you won't open the door!

Knock knock. Who's there? Flour.

Flour who? I knead you to let me in, it's a loaf-ing matter.

Knock knock. Who's there? Maple.

Maple who? Maple you a favor and open the door!