The line comes from Gumball Watterson, the main character of Cartoon Network's The Amazing World of Gumball, a surreal animated series that mixed 2D and 3D animation and became widely quoted online. Short reaction lines from the show were clipped and shared on soundboards and social video platforms, where creators reused them to punctuate disbelief without needing context from the episode. The phrase works because it is instantly recognisable, family friendly and easy to drop into edits, keeping it in circulation alongside other confused reaction clips such as You What?