Knock knock. Who's there? Dew.

Dew who? Dew-n't worry, it's just a drop in.

Knock knock. Who's there? Cows go.

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

Knock knock. Who's there? That's what I'm asking.

That's what I'm asking who? That's what I'm asking who wants to know who's on the other side of this door!

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?