Coffee has carcinogens, causes cancer. And it also has caffeine. So not only are you dying, you watch yourself go.

In this line, Jackie Mason uses a mock-logical, medical-sounding setup (“carcinogens,” “causes cancer”) to parody health panics and the way everyday pleasures get reframed as lethal risks. The punchline hinges on caffeine’s stimulant effect: if coffee is supposedly killing you, it also keeps you alert enough to experience the process in real time—“you watch yourself go.” The humor comes from exaggeration and the collision of clinical language with a bleak, existential image. It also reflects a common stand-up theme: modern life’s constant warnings and contradictions, where even small comforts are presented as dangerous, yet people keep consuming them anyway.