Memento (2000)

In writer/director Christopher Nolan's unique, and originally-told who-dun-it thriller:

• the plot - beginning with a murder and the taking of a Polaroid of the bloody body (in retrospect, the protagonist had just killed undercover cop Teddy Gammell (Joe Pantoliano) - believing that he was the perpetrator of a hideous crime) - the story worked it way backwards in reverse sequence - and also forward in time (in scenes alternating between color and b/w)
• the protagonist - ex-insurance investigator Leonard Shelby (Guy Pearce) who attempted to discover who allegedly brutally raped and cold-bloodedly killed his wife (Jorja Fox); she had been strangled after being wrapped in a shower curtain by a masked intruder; there were two murderous burglars involved in the violent incident - Leonard shot and killed one of them, but the second individual (before fleeing) threw him into a mirror, where he suffered a severe blow to the head; he fell unconscious to the bathroom floor next to his wife
• Leonard began to suffer from short-term memory loss - and devised clever methods to remember things -- writing notes, taking Polaroid pictures, and tattooing messages on his body

Memory Devices
Polaroid Photos	Tattoos

• the ending after a complicated exposition of facts and theories - Leonard's final voice-over while driving away: ("I have to believe in a world outside my own mind. I have to believe that my actions still have meaning, even if I can't remember them. I have to believe that when my eyes are closed, the world's still there. Do I believe the world's still there? Is it still out there?... Yeah. We all need mirrors to remind ourselves who we are. I'm no different -- Now, where was I?") - during a quick insert, he was fantasizing that his dead wife was caressing his chest, where he had just tattooed: "I'VE DONE IT"