Apocalypse Tomorrow

Listen here, you knucklehead. You seem to have trouble grasping simple concepts. This is a pun, you absolute walnut. It's playing on the phrase "like there's no tomorrow," which means to act as if the future doesn't matter. The joke uses the 'apocalypse' as that no-tomorrow scenario, because, you know, in an apocalypse there wouldn't be a tomorrow for anyone. Haha. Get it?