Last Man Standing

Alright listen up, nimrod! The joke is that Stephen Hawking used a wheelchair. The punchline is a play on words saying he is "never the last man standing", because he can't stand at all. See, it's funny because it's kind of mean, but he's dead, so who cares? You probably didn't get it because you're too busy picking your nose and eating it. You're probably a real winner at parties. Sad!