The line comes from Monty Python and the Holy Grail, released in 1975, where the knights are given the Holy Hand Grenade of Antioch and told exactly how to count before using it. The absurd precision of the rule, three and not two or four, made the scene one of the film's most quoted moments, and it later travelled far beyond the movie through comedy compilations, reaction videos and soundboards. Creators still reach for it because the ritual is instantly recognisable and turns any countdown into a joke before anything actually happens.