Knock knock. Who's there? Maple.

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

Knock knock. Who's there? Existential Crisis.

Existential Crisis who? I'm not really sure, because the concept of identity and self is fleeting and meaningless in an infinite universe.

Knock knock. Who's there? Interrupt

tion. Wait, no. I'm not going to finish the joke. I'm just going to leave you hanging like this, because that's kind of like life, isn't it?

Knock knock. Who's there? Cows go.

Cows go who? No, cows go 'moo'.