Reality Subtext: Gatsby and Daisy's relationship is not dissimilar to that of Scott and Zelda Fitzgerald, though it has more in common with the relationship between Scott Fitzgerald and Ginevra King.
Write What You Know: It's believed that Daisy was based off of Ginevra King, Fitzgerald's ex-girlfriend who was also a rich Chicago socialite. Likewise, Tom is believed to have been based off of William Mitchell, the man who Ginevra eventually married. Fitzgerald himself confirmed that Jordan was based off of Edith Cummings, one of Ginevra's friends.
The 1926 film:
Disowned Adaptation: Scott and Zelda Fitzgerald walked out of a screening of the 1926 silent film (the only one released during their lifetimes), which emphasized the party scenes and their scandalous elements.