Poster for the film 'Memento', 2000.

'Memento' is a 2000 American neo-noir psychological thriller film written and directed by Christopher Nolan, based on a pitch by Jonathan Nolan, who later wrote the story "Memento Mori" from the concept. Guy Pearce features as a man who, as a result of an injury, has anterograde amnesia (the inability to form new memories) and has short-term memory loss approximately every fifteen minutes. He is searching for the people who attacked him and killed his wife, using an intricate system of Polaroid photographs and tattoos to track information he cannot remember. The film is presented as two different sequences of scenes interspersed during the film: a series in black-and-white that is shown chronologically, and a series of color sequences shown in reverse order (simulating for the audience the mental state of the protagonist). The two sequences meet at the end of the film, producing one complete and cohesive narrative.

Many medical experts have cited Memento as featuring one of the most realistic and accurate depictions of anterograde amnesia in the history of motion pictures. Caltech neuroscientist Christof Koch called 'Memento' "the most accurate portrayal of the different memory systems in the popular media", while physician Esther M. Sternberg, Director of the Integrative Neural Immune Program at the National Institute of Mental Health, identified the film as "close to a perfect exploration of the neurobiology of memory."

In 2017 the United States Library of Congress deemed the film "culturally, historically, or aesthetically significant" and selected it for preservation in the National Film Registry.