As you've probably heard by now, Baz Luhrmann's 3D, $100 million film adaptation of The Great Gatsby hits theaters today — but it sure took its time getting here. (Watch a trailer for The Great Gatsby below.) As reviews for the film pour in, it's easy to forget that it took nearly a decade for The Great Gatsby to come together, and there were no shortage of bumps along the way. Here, six things you might not have known about Luhrmann and his long-in-the-works project: 

1. Baz Luhrmann first decided to adapt The Great Gatsby in 2004
Luhrmann first decided to adapt Fitzgerald's novel after listening to an audiobook version during an extended train trip in 2004. "The train was basically full of Chinese people smuggling stuff into Mongolia," said Luhrmann in an interview with The Hollywood Reporter. "I had two bottles of red wine and the new iPod with two recorded books. There's Siberia ticking by, and the birch trees, and the wine bottle, and I'm listening [to Gatsby] — and when it ended, I had inconsolable melancholia. I was like, 'Can we do all that again?'" After negotiating with the producers at Sony who owned the rights to the novel, he approached Leonardo DiCaprio, whom he'd last worked with in 1996's Romeo + Juliet. DiCaprio was the only actor Luhrmann ever approached for the role of Jay Gatsby.

2. Carey Mulligan wasn't originally considered to play Daisy Buchanan
After his poorly received Australia hit theaters in 2008, Luhrmann dedicated himself to getting The Great Gatsby off the ground. In 2010, Luhrmann did a workshop of his Gatsby screenplay in which Iron Man 3's Rebecca Hall read for the part of Daisy opposite DiCaprio and Tobey Maguire. But according to Deadline, Luhrmann quickly decided to cast a wider net for the role of Daisy. The early list of favorites for the role was a who's-who of Hollywood's hottest young actresses, including Natalie Portman, Keira Knightley, Michelle Williams, Scarlett Johansson, Amanda Seyfried, Abbie Cornish, and Blake Lively — but not Carey Mulligan. "I only found out about it three days before the audition, so I read the book for the first time and went to see [Luhrmann]," said Mulligan in an interview with The Hollywood Reporter. It wasn't until weeks after the audition that Luhrmann finally called her to tell her she had won the role.

3. Bradley Cooper wanted to play Tom Buchanan
In 2011, fresh off the success of The Hangover — but before Silver Linings Playbook earned him both a reputation as a serious actor and an Academy Award nomination — Bradley Cooper spoke enthusiastically about his interest in playing Tom Buchanan, Daisy's boorish husband, in the film. "To me, he's the best character in the book," said Cooper in an interview with The New York Times. "He's so complicated. He's xenophobic, he's an alcoholic, but he also understands some profound stuff about class. Whoever plays it has to take a gentle hand, because it could so easily be stock, where he's a rich jerk you don't identify with at all. […] I don't even know if I'm on Luhrmann's radar. Maybe he'll read this article after the role's cast and say, 'Oh. Ha. Yeah, that guy was never going to get it.' "

4. Ben Affleck was originally cast as Tom
As it turns out, Cooper's doubts about his chances for the role were justified. Whether or not Cooper was ever really in the running, Luhrmann had settled on Ben Affleck as Tom in the film. In the end, Affleck abandoned the role to direct and star in Argo, which went on to win Best Picture at the Academy Awards last year — so yeah, he probably made the right call. Zero Dark Thirty star Joel Edgerton was eventually cast in the role.

5. The soundtrack is designed to evoke the spirit of the jazz era
Purists have balked at The Great Gatsby's anachronistic, Jay-Z-produced soundtrack, which features everything from a Beyonce Knowles/Andre 3000 cover of Amy Winehouse's "Back to Black" to a Jack White cover of the U2 song "Love is Blindness." But the offbeat selections serve a thematic purpose, explains Luhrmann at Rolling Stone: "The question for me in approaching Gatsby was how to elicit from our audience the same level of excitement and pop cultural immediacy toward the world that Fitzgerald did for his audience? And in our age, the energy of jazz is caught in the energy of hip-hop."

6. Baz Luhrman wants to collaborate on another literary classic with DiCaprio
The Great Gatsby performed very well at midnight screenings on Thursday night, and it's on track to earn Luhrmann's biggest opening weekend gross of all time. So what's next for Luhrmann and his favorite leading man? "Hamlet," says Luhrmann in an interview with The Hollywood Reporter. "To me, Gatsby is the American Hamlet. What else could we possibly do as a follow-up?" For now, Luhrmann concedes that a DiCaprio-led Hamlet is "just a dream" — but given how his dream about Gatsby turned out, it's entirely possible that this one will eventually come true.