If you haven't already, you're going to hear a whole bunch of gripes about "The Great Gatsby" movie out this weekend. And the biggest of them all will likely have something to do with how faithful it was to the classic F. Scott Fitzgerald novel.

Needless to say, there are some significant changes. But there are significant changes in "Iron Man" when put up against the comic books -- sometimes change is necessary, and even good. Then again, sometimes they're not.

We've narrowed it down to five key differences between Baz Luhrmann's adaptation and the Fitzgerald text (other than that whole Jay-Z thing) so you can be mentally prepared, for better or for worse.

Nick Carraway is in a sanitarium.

While it's never abundantly clear that narrator Nick Carraway (Tobey Maguire) is "writing" the book you're reading, he's certainly not writing it from a sanitarium. In the text, Fitzgerald merely alludes to Nick as the scribe -- within the first couple paragraphs, he describes Gatsby as "the man who gives his name to this book" -- but doesn't say so explicitly. In the film, Nick is writing from a sanitarium, where he's checked himself in sometime following his summer with Gatsby and has been diagnosed as a "morbid alcoholic," among other things.

Viewers are introduced to this concept in the very beginning and also see the point at which Nick begins to write the manuscript. Additionally, Luhrmann often flashes forward to Maguire to remind them that he's a writer. Of course, this isn't the first time the director has taken such a storytelling approach -- "Moulin Rouge" was also told from the perspective of a writer, and both films frequently show their would-be authors pecking away at a typewriter.

Lastly, one of the movie's final images is Nick adding "The Great" to the title of his finished "Gatsby" manuscript with a flourish. The book, however, leaves its reader only with the juicy final image of "So we beat on, boats against the current, borne back ceaselessly into the past."

Nick and Jordan Baker were definitely a thing.

In the movie, prepare to see Nick and chic golfer Jordan Baker (Elizabeth Debicki) flirt but never actually hook up -- Nick's just too smitten with Gatsby to notice her. The novel, however, has them strike up a hot little fling.

"I put my arm around Jordan's golden shoulder and drew her toward me and asked her to dinner," Fitzgerald wrote following their tea date, later adding, "I drew up the girl beside me, tightening my arms. Her wan, scornful mouth smiled, and so I drew her up again closer, this time to my face."

Seeing as Nick then writes about getting home at 2 a.m., that seemed to have worked out pretty well for him.

Jay Gatsby makes a grand entrance.

Actually, this is true of both the book and the film, but you can't exactly have Nick unknowingly interacting with Gatsby when he's played by Leonardo DiCaprio. The jig would be up.

In the novel, Nick is at one of Gatsby's big bashes when he strikes up a conversation with "a man of about my age." They swap war stories and make plans for the next day until Nick confesses that he has yet to meet the host of the party. "I'm Gatsby," he says. "I thought you knew, old sport. I'm afraid I'm not a very good host."

Racism and anti-Semitism has been removed.

Much has already been written about the casting of Indian actor Amitabh Bachchan as the Jewish Meyer Wolfsheim, but we agree with Slate that faithfulness to the text would have been downright anti-Semitic. After all, Fitzgerald describes him in decidedly less than flattering terms: "A small, flat-nosed Jew raised his large head and regarded me with two fine growths of hair which luxuriated in either nostril."

Tom Buchanan (Joel Edgerton) was also notoriously racist, spouting off about a book called "Rise of the Colored Empires" and otherwise. Needless to say, this is one change we applaud Luhrmann for.

Gatsby died thinking he was a winner.

Don't worry -- it's still George Wilson (Jason Clarke) who kills Gatsby, he's still lonely and pitiful, and his pool is still involved. It's just the phone that's quite a bit different in the new movie.

In both, our anti-hero is waiting for a call from Daisy and decides to go for a swim. While the book has him climbing aboard a float, his butler waiting for the call "until long after there was any one to give it to if it came," and his chauffeur hearing the shots, the movie takes a much more showy approach. Instead, Gatsby takes a dive into the water and steps out as the phone rings. Wilson takes his shot at that very moment and Gatsby dies thinking he may have gotten the girl, that Daisy (Carey Mulligan) was calling to say she was leaving Tom and running away with him.

Of course, audiences know differently: that it was only Nick on the phone.

We want to hear from you -- do you think some of these changes were for the best? Or are you frustrated that Baz Luhrmann took such liberties with such a classic novel? Let us know in the comments, but keep in mind: Even Fitzgerald got panned when the book was first released.