Leonard (Guy Pierce) is running, but he can't remember if is he being chased or if he is the chaser. Leonard spits in a drink; just minutes later, he gulps it down, not remembering his expectoration. Leonard has some problems. Since being hit on the head during an attack on his wife, Leonard can only remember events from two time periods: before the attack, and within the past five to ten minutes.

In Memento, director Christopher Nolan presents Leonard's experience to the audience in those same five- to ten-minute segments, with one twist: the segments are in reverse chronological order. The film's inverted path manages to put viewers as close to Leonard's predicament as possible without confusing them. When the film starts and Leonard sees a note telling him to kill Teddy, we have exactly the same information that Leonard has: we know Leonard wrote a note to himself that told him to kill Teddy, and that's all we know. There is constant excitement in watching Leonard do as much as possible before he forgets why he's doing it.

Memento would be an impressive instance of film storytelling even if it had nothing important to say, but it does. While many films in the past few years have played with chronology, Memento's triumph is to use the nonlinear structure to embellish the theme--which is the clash between our need to trust ourselves and our inclination to tell ourselves only what we want to believe.