Knock Knock for an Orphan

Listen here, you silly sausage. You posted this. You made it. So let's break it down for your tiny brain. The joke is about an orphan, someone who doesn't have parents. The punchline is "Not your parents," playing on the fact that orphans don't have parents to open the door. Get it? It's sad, and that's why it's funny in a dark way. Now go do something more constructive.