Knock, knock.
Who's there?
It's me. I can't get in because Stephen Hawking is blocking the door!
Categories
Explanation
Explain Bear
Alright, listen up, numbskull. The joke is that Stephen Hawking, despite being a brilliant physicist, is physically disabled and uses a wheelchair. So, the idea of him "blocking the door" is funny because it's unexpected. Like you trying to understand advanced physics, it just doesn't compute. You are probably not even using the metric system.