This phrase comes from informal American slang for expressing disbelief, and the clip circulates online as a short reaction sound rather than a line tied to one widely documented film or show. It gained traction on soundboards and short-form video because the wording is instantly recognisable and the delivery feels unscripted. Creators reuse it to punctuate confusion, disagreement and sarcasm, often pairing it with captions or stunned facial expressions. Its staying power comes from that versatility: almost any unbelievable statement can be followed by this blunt challenge.