Scriptwriter Charlie Kaufman felt dissatisfied with the way George Clooney treated his script. He commented: "I spent a lot of time working on the script, but Clooney wasn't interested in the things I was interested in. I've moved on, and I've no animosity towards him, but its a film I don't really relate to." Clooney acknowledged he made changes, because there were 'funky scenes' that never would have got the greenlight for a studio film.
After his training, Chuck says goodbye to "Jack" and "Lee." Considering popular conspiracy theories regarding the John F. Kennedy Assassination, this is clearly a tongue-in-cheek reference to Jack Ruby and Lee Harvey Oswald.
The film was spoofed in a brief article in The Onion entitled "Movie Marketed as Six Different Genres" ("a romantic comedy, a spy thriller, a Hollywood satire, a straightforward biopic... a strange, Being John Malkovich (1999)-esque mind-bender," and a chick flick).