For most movie-going audiences, it's a pretty basic requirement that a film makes some sort of sense, that it adheres to some form of narrative logic which allows them to connect with it on the most basic level.
And while there are certainly films which make no sense at all despite their efforts - looking at you, Batman v Superman - there are also those which intentionally obfuscate meaning until a pivotal final reveal.
These 10 films all took major dramatic gambles by concealing their true narrative intent until the eleventh hour, at which point the obscure narrative and unclear character motivations all clicked firmly into place.
While this certainly makes each of these films potentially frustrating for audiences, especially on a first viewing, it does also result in a deeply satisfying climactic revelation, a blissful lightbulb moment as everything becomes fully illuminated.
And of course, it goes without saying that each film makes decidedly more sense on a second viewing with its full context in the front of your mind...
Christopher Nolan's noodle-baking mystery-thriller Memento thrives on the fact that both Nolan and protagonist Leonard Shelby (Guy Pearce) are holding something back from the audience.
The film's ingenious narrative structure unfolds in reverse-chronological order, interjected with black-and-white cutaways running in the opposite direction, all of which is intended to simulate to the viewer the sensation of Shelby suffering from amnesia.
As a result, the viewer's first path through Nolan's film is a mightily bewildering one, and though the narrative effectively snowballs context the closer it gets to its incredible ending, only in the film's final moments does it all tie neatly together.
With audiences following Leonard throughout the movie on his journey to catch his wife's killer, it all leads up to a sobering mic drop of an ending.
It's revealed that Leonard in fact killed his own wife accidentally with an insulin overdose, and in order to escape the guilt, has constructed an elaborate revenge narrative with which to deceive himself within his own amnesia-distorted mind.
As a result, Memento is a film which begs the audience to watch it again, because once you finally know what's up, the second go-around is far more richly rewarding.