Der Schnurrbart (2005)

One day, on a whim, Marc decides to shave off the moustache he's worn all of his adult life. He waits patiently for his wife's reaction, but neither she nor his friends seem to notice. Stranger still, when he finally tells them, they all insist he never had a moustache. Is Marc going mad? Is he the victim of some elaborate conspiracy? Or has something in the world's order gone terribly awry?