The line comes from the 1998 Coen brothers film The Big Lebowski, spoken by Jeff Bridges as Jeffrey Lebowski, better known as The Dude. In the film it captures his easygoing, conflict-avoidant philosophy, and that attitude helped it outlive the movie itself. Clipped from the dialogue, it spread through soundboards, reaction videos and social media as a short way to dismiss a strong opinion without sounding angry. Its staying power comes from its versatility: it fits arguments, jokes, reviews and everyday disagreements almost anywhere.