What do we mean when we say it today?
Knock, knock.
Who's there?
We bet you're waiting for the punch line. In our modern world, this is a classic set up for a classic joke. We've heard this whole routine over and over again since we were kids. The Porter's laugh-a-minute style in this scene launched a whole series of "knock-knock jokes."
But none of these knock-knock jokes involve anything close to the tension and anxiety that is happening in this scene in Macbeth. In fact, they're quite the opposite. Knock-knock jokes are one of the tamest jokes around. That's why they're used with kids so much.
Isn't that ironic? We think it's pretty hilarious that we've taken a line from a scene discussing treason, murder, and politics and made it into a charming little joke for kids. And next time you hear a knock-knock joke, we bet you won't just be thinking about who's there.