The movie is dark, perhaps portraying a mind full of clutter, not allowing lucidity to flow. The scene at the end where the lead character draws a very big and long yawn, driven to somewhere, anywhere by a stranger in a Kombi van sums up what I think the writer intended to convey.
That when we are driven by the mind which is a stranger to us in as far as how it reacts and the consequences thereof, the journey is pointless and tiring with the only silver lining being that we seem to be progressing to somewhere. The ennui (or thrill?) of continuously reacting takes away from living. The world that we inhabit is dark only because the prism of our perception is fogged by our continual huffing, puffing, praying, reacting...