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? 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? Wu

Wu who? Wu don't know, it's a Chinese puzzle to me, but I'm paws-itive I'll figure it out, fur-get about it!

Knock knock. Who's there? Sewers.

Sewers who? Sewers *nice* of you to ask, but these puns are really *sewers*-ing my patience, making me think it *sewers*ly time to *sewers*-t out a new joke writer!