1. The poem that one of the personality claims was written when he was a child "As I was going up the stair/I met a man who wasn't there/He wasn't there again today/I wish, I wish he'd go away "It's actually a poem written by Hughes Mearns.
2. The book Paris picked up in Ed's car was "Being and Nothingness" by Jean-Paul Sartre.
3. This is the last film of Frederick Coffin.
4. It is the machine spray gun that makes the rainstorm, and the water inside is heated to an appropriate temperature in advance to protect the actors. However, during the entire shooting process, the heavy rain "dropped" for 40 days and 40 nights, and only Ed was wearing a raincoat.
5. In order to hide the secret of the real ending, a total of several endings were filmed.
6. The probability of the same birthday of ten personalities is about 1 in 115,694,315,636,972,669,502,854.
7. Timmy has only one line of dialogue in the whole movie, and even this one was said by Malcolm first.
8. The naked man tied to the bed by Paris at the beginning of the movie is one of Malcolm's personalities; he is also the agent who called Caroline Suzanne (female star). He was originally the first personality to die in the movie, but his role was deleted.
9. Alice York (the child's mother) was sometimes replaced by a mannequin during filming, just like she had just died.
10. The body of the hotel owner hidden in the refrigerator by Larry was played by Stuart M. Besser, who was also the executive producer and producer of this film.
11. At the end of the film, when Ed shoots Rhodes with a gun, you can see Rhodes saying "I didn't do this" and Ed replied "I know". These two sentences are not heard, they are eliminated, because the director thinks that these two sentences will make Rhodes not a killer obvious, so that the real climax of the film (that is, the discovery that Timmy is the murderer) is no longer so pleasant.
12. Most films have more than 50 scenes, and this film has only one-the hotel in the desert. So the set designer worked hard to arrange this unique scene into multiple levels.
