The line comes from Monty Python and the Holy Grail, the 1975 comedy film, in the scene where King Arthur fights the Black Knight guarding a bridge. After Arthur cuts off the knight's arm, the knight brushes the wound aside with the phrase, and keeps fighting even as he loses more limbs. The exchange became one of the film's most quoted moments, and clips of it spread widely online as a reaction sound for stubborn denial. It endures because the understatement is instantly recognisable even to viewers who have not seen the full film.