With the Oscars fast approaching, director Ethan Coen is reflecting on why Western movie True Grit has been his biggest hit.
"It's a notoriously fickle, flukey, unpredictable business," he says ahead of the film's UK opening.
"I won't be able to explain, but it's very gratifying. It's done better than any of our other movies by a long shot."
Ethan and older brother Joel - more commonly known by the collective Coen Brothers tag - enter the Oscars race this year with an impressive track record.
Their drama A Serious Man was nominated for best picture last year, and they won the top prize for 2007's No Country For Old Men.
Their films have garnered them 33 Academy Award nominations over the past 18 years.
Their latest film, True Grit, is up for 10 Oscars and has been the brothers' biggest commercial success, with worldwide takings exceeding $175m (£108m).
The story sees US Marshal Rooster Cogburn (Jeff Bridges) helping teenage farm girl Mattie Ross (Hailee Steinfeld) and Texas Ranger LaBoeuf (Matt Damon) track down the girl's father's killer, Tom Chaney (Josh Brolin). Both Bridges and Steinfeld are Oscar-nominated.
The Coens established themselves as leading lights of US independent cinema scene with self-penned films like Raising Arizona, Miller's Crossing and Barton Fink.
The last decade, though, has seen them adapting pre-existing works like Ealing comedy The Ladykillers and Cormac McCarthy's No Country for Old Men.
True Grit is the Coens' reboot of the Charles Portis novel that was filmed in 1969 with John Wayne as Rooster Cogburn.
"It's a very funny book," explains Coen. "It's told in the voice of this 14-year-old character who's prematurely sure of herself and sure of everything. It's got three great main characters, and each funny in their own way. It's a simple revenge story and it seemed like promising material.
"Joel and I had both read it years ago. Joel re-read it a couple of years ago out loud to his son and that's what prompted him to think it would be interesting to make this movie."
The Minnesota-born siblings were anxious not to recreate the original film which won John Wayne his only Oscar. "We'd seen the 1969 movie when it came out, and we weren't thinking about that film at all, just the novel."
Ethan Coen hasn't watched it since. "I saw the trailer for it on the internet and I thought wow - that is wow - wow! It's of its time."
Although True Grit has been heralded by many as the resurrection of the Western, Coen doesn't see it in genre terms.
"It's not a genre story, it does have people in cowboy hats and it does have six-shooters, but it's really about the characters and the story."
While it sticks closely to its source material, the film does contain some unmistakeable Coen touches. The first time we meet the one-eyed, whisky-swilling Cogburn - he's ensconced in an outside toilet.
"Yeah, why did we come up with that?" laughs Coen. "That's one of few scenes that does not derive from the original novel. We were thinking how to create a little bit of suspense about this character, who's been talked about already.
"We asked Jeff when we were shooting - 'Jeff, first outhouse scene?' And he said 'Yeah, I haven't done one of those before.' It was a first outhouse scene for everybody. It's a way of meeting him, but kind of not."
True Grit marks the first time the Coens have worked with Jeff Bridges since 1998 cult favourite The Big Lebowski, in which he played the ultimate Californian slacker, known simply as The Dude.
Says Coen: "It was as easy as the first time. He knows what he's doing to such an extent that was easy. We and Jeff assumed we would work together after The Big Lebowski and it's just a surprise that it's taken so long."
True Grit marks the movie acting debut of Hailee Steinfeld, who shot the film when she was 13. Did the Coens do anything differently having a young newcomer on set?
"Not really, she's so much an actor as opposed to a kid on a movie set that you forget her age. The only ways in which you are aware of it are totally negative things like work rules about hours you can work with minors. That's a pain, but otherwise it was like working with Matt or Jeff."
Unusually for a Coen brothers film, True Grit opened in the US with a PG-13 rating (it's rated 15 in the UK).
"I'm sure that's helped the film's success," Coen observes. "We were hoping it would not have a restrictive rating because it is a story about a 14-year-old girl and it is a novel that 14-year-olds can read and enjoy - so we thought kids should be able to see this movie."
True Grit was released in the UK on 11 February.