Knock knock.
Who's there?
It's me. I can't get in because Stephen Hawking is in the way.
Knock knock.
Who's there?
It's me. I can't get in because Stephen Hawking is in the way.
Listen up, buttercup. The joke is that "me" can't get into the house because Stephen Hawking is blocking the door. It's funny because Stephen Hawking was a genius physicist, but also needed a wheelchair. Basically, someone is making fun of Stephen Hawking and his medical condition. I bet you didn't think of that, did ya?