- Adaptation First: It's based (very loosely) on the short story "Memento Mori" by the director's brother but that story wasn't published until after the film opened. It's included on the DVD. The short story actually has a lot in common with The Dark Knight, as many of Earl/Leonard's inner monologues are The Joker's verbatim.So the question is not "to be or not to be," because you aren't. The question is whether you want to do something about it. Whether revenge matters to you. It does to most people. For a few weeks, they plot, they scheme, they take measures to get even.
You probably were the type to let it go, weren't you? Before. But you're not the man you used to be. Not even half.
Never-ending grief, never-ending anger. Useless without direction.
- Breakthrough Hit: It was Nolan's first big hit as a director.
- Cast the Expert: Stephen Tobolowsky has stated that during his audition for Sammy, he had mentioned to Christopher Nolan that he had experienced amnesia personally. A few years earlier, he was given an experimental pain killer that induced amnesia for a surgery he had undergone. Tobolowsky said it may have helped him get the part, because no other actor would likely have had his first-hand experience.
- Dyeing for Your Art: Guy Pearce was originally two hundred thirty pounds (104.3 kilograms) before the movie was made, and lost all of the weight within a few months.
- Fake American: Guy Pearce as Lenny.
- From Entertainment to Education: The film has been used to better understand anterograde amnesia (that is, the inability to create new memories)
- Shrug of God: The DVD Commentary splits into three parts in the last scene: one saying that Teddy was lying to Leonard, one saying he is telling the truth, and one not saying either way.
- Throw It In!:
- Many of Leonard's unique voiceovers were improvised by Guy Pearce.
- All of the dialogue in black-and-white sequences that feature Sammy was improvised.
- What Could Have Been:
- Christopher Nolan's first choice for the role of Leonard was Alec Baldwin. Aaron Eckhart, Thomas Jane, Brad Pitt, and Charlie Sheen were also considered.
- Famke Janssen, Ashley Judd, and Angelina Jolie were considered for Natalie.
- Denis Leary turned down the role of Teddy.
- "Paranoid Android" by Radiohead was originally going to be used in the closing credits, but Nolan decided that the royalties needed to use this song (owned by Capitol Records) would be too great for this low-budget film.
Trivia / Memento