The generic stand-up comedian when he goes "Any of you guys smoke weed? You get hungry when you smoke weed, don't you?" just so the audience will laugh because he's talking about weed. It's like how in college all a TA has to do is throw in some swears and the class will all laugh like we've never heard an adult swear in public. There are good comedians with good bits involving weed, but you know what I mean.
When people misinterpret alcohol being a depressant as alcohol making you sad. "Why would someone take a depressant if they're already tense?" or whatever similar saying.