The line comes from Star Trek: The Next Generation, in the two-part episode Chain of Command, first broadcast in 1992. Captain Picard, captured and tortured by the Cardassian Gul Madred, is shown four lights and ordered to say there are five. His refusal became one of the series most quoted moments, later clipped for YouTube compilations, reaction videos and Star Trek memes. It endures because it works beyond the show, as shorthand for holding firm to an obvious truth when someone in power demands otherwise.