Knock knock. Who's there? Cows go.

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

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? Noah.

Noah who? Noah body's home, I'm ark-ing around for someone to let me in.

Knock knock. Who's there? Oblivion.

Oblivion who? *everything ceases to exist*