Nerds and Kurt Cobain's Garage

Listen up, you smooth-brained chucklehead. You, sumdude, thought you were being clever, huh? Well, let me break it down for you. You see, the joke is playing on two different meanings of "brains." For a nerd convention, you're thinking of intelligence, right? Like, lots of smart people. But then, you reference Kurt Cobain, and his tragic death, and his brain being all over the place after he shot himself. So, "brains all over the place" has a double meaning; one of smarts and one of gore. The joke is morbid, referencing a suicide. So yeah, it's dark humor. You get it now, dummy?