Nicolas Cage has said that during the filming of this movie, he ignored all of his acting instincts and played the part of Charlie Kaufman exactly as director Spike Jonze asked him to. He then received an Academy Award nomination for it.
To portray John La Roche, Chris Cooper grew out his hair, shed weight and used a prosthesis to create the illusion of a toothless mouth. Spike Jonze granted Cooper's request for numerous takes so he could find the right tone for the eccentric character.
In his renowned screenwriters seminars, Robert McKee now makes note that he is not against the use of voice-over narration, "despite what Charlie Kaufman says." His point is voice-over narration must add to the story, not describe what's already being seen on the screen, otherwise there's no reason for it.
Based on writer Charlie Kaufman's struggle to adapt the best-selling book "The Orchid Thief" by Susan Orlean. Kaufman quickly got writer's block, since the book lacked the dramatic structure needed for a movie. So he decided to write a screenplay about himself struggling to write a book adaptation, exaggerating many of the story elements and characters, and making up new ones (such as a non-existent twin brother, Donald Kaufman.) Knowing that the producers would reject the idea, he did not tell them about the new direction in which he was taking the story, and simply handed in the finished script. Although this move was supported by Spike Jonze, Kaufman himself believed it would end his career, but it didn't.
Charlie comes home and checks his mail. He is in front of a mirror, and Donald is talking to him behind him. The reflection of Donald in the mirror is actually the real Charlie Kaufman.
David O. Russell: One of the Orleans' dinner guests is the director of Three Kings (1999), in which Spike Jonze appeared.