Memento in its initial concept seems like a novelty film, and with an initial viewing it can be enjoyed as such. That being you uncover a mystery by going from each scene in reverse rather than in normal chronological order. It works in that way as each scene remains compelling and the mystery remains fascinating while the approach never becomes repetitive. Christopher Nolan utilizes the concept brilliantly and succeeds in making a one of a kind film. However I don't think the film simply works based on the execution of the concept, which though notable, the film can be re-watched even after you know the secrets it holds. It's a far richer film than that. This is even found just in the almost suprising abudance of humor that so naturally utilized throughout the film, that proves Nolan is more capable of comedy than some give him credit for. There also is a powerful emotional core to the film realized through Guy Pearce's great performance that never loses the human element of what compels Leonard on the path which is not as simple as it might seem. Even in the progression of the mystery this is never lost, especially in Leonard's recounting of the story of a man with the same problem he has, though maybe that story isn't even quite as it seems. It's an amazing film since it never defines itself by the novelty but rather uses it to tell a great story.