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In a 2013 interview with Terry Gross, Joel Coen told a story about having recently been at a movie theater in San Francisco, California, where they saw a booth displaying Lebowski posters. Ethan Coen asked the teenage girl there what was going on, and she proceeded to tell him about the theater's nightly screenings of the movie. She said that people come dressed in costumes, "and you should come and you'll like it, it's fun." She had no idea that the two men had made the movie.
In an interview with Rolling Stone Magazine, John Goodman stated that The Dude referring to The Big Lebowski as a "human paraquat" was one of the only improvised lines to make it into the final film. Virtually every other line, including every "man" and "dude," was scripted.
Before filming a scene, Jeff Bridges would frequently ask the Coen brothers "Did the Dude burn one on the way over?" If they said he had, he would rub his knuckles in his eyes before doing a take to make his eyes appear bloodshot.
A lot of the Dude's clothes in the movie were Jeff Bridges's own clothes, including his Jellies sandals, which he still owns and uses to this day.
While being a member of the Bowling team, the Dude is never seen bowling.
Asia Carrera: The girl appearing opposite Bunny Lebowski and the nihilist in the porno that Maude shows The Dude is a porn star.
Charlie Kaufman: In the audience during the interpretive dance scene. Kaufman's own script, Being John Malkovich (1999), also contains an interpretive dance sequence.