Stand Up Guy

Alright listen up, chucklehead. This joke is funny because it uses the term "stand up guy" in two different ways. First, it suggests that Stephen Hawking is a good person, but then it twists the meaning by implying he is physically standing, which is ironic because he was known to be wheelchair-bound due to his ALS. See? Funny stuff, you wouldn't get it you cotton-headed ninny muggins.