The line comes from Seinfeld, the long-running American sitcom about Jerry Seinfeld and his friends in New York, where Elaine Benes, played by Julia Louis-Dreyfus, often delivered 'Get out!' as a shocked, playful dismissal, usually while giving someone a shove. The moment became one of her most quoted reactions, and short clips of it later circulated on soundboards, reaction videos and social edits. It endures because the phrase is instantly recognisable, needs no setup, and fits almost any moment of comic disbelief or rejection.