When we think of a "complex" movie, we tend to think of disjointed narratives, ambiguous characters, a state of bewilderment. It's almost as though a complex movie, by definition, has to beat you into submission with its intelligence in order to prove itself. This, in turn, makes it worthy of obsession... or at least a rewatch.
Some movies shoot for complexity and come up short, of course: Shutter Island, to cite one example, is impressively labyrinthian in its structure, but the final plot twist fails to explain the central conceit in a way that is narratively logical or satisfying. You come away feeling as though the film was complexfor the sake of it.
Occasionally, though, a properly complex movie emerges; one that can actually justify its reputation for head-scratching and limitless pondering. In a lot of cases, audiences aren't expecting to come face to face with films made in this vein: in the advertising material, they're pitched or marketed one way, and only later - in theatres - do they reveal themselves to be works of legitimate cerebral power.
In short, it's easy to be sidelined by a movie's unexpected complexity, as made evident in the bold and original films gathered here...