Summarize the following movie reviews:

1. A very clever, complex and extremely well constructed movie which demands intelligence and constant attention from its viewers, yet is put together using only a handful of simple elements.
2. Walking out of Memento, we can be glad that we don't share Leonard's amnesiac condition; it's the kind of film you don't want to forget.
3. It's absolutely brilliant--a terrific little thriller that takes the genre and turns it inside out.
4. MEMENTO is not just a movie, but a puzzle.
5. Although gimmicky at times, Memento takes an innovative approach at storytelling that yields a surprising amount of mystery and suspense.
6. A con in the mode of Bryan Singer's The Usual Suspects--the scam of the year.
7. A film that simply gets so much right that there doesn't seem to be anything of real worth left to say about it once you see it.
8. A joyously twisted Rubik's Cube of a movie. One of the year's best films.
9. Christopher Nolan's extraordinary film is a brainteaser and a heartbreaker.
10. Films so seldom take chances anymore, it's refreshing to see one that at least tries for something different.
Christopher Nolan skillfully guides the audience through Memento's fractured narrative, seeping his film in existential dread.