“The Birdman” is neither fiction nor a documentary. By imagining the story of a young man who sets out to find his past in the city of Los Angeles, the film documents the impossibility of returning to the places left behind. Through its effort to document what once was, it dives into the imagination to see what cannot be seen otherwise. Shifting between documentary and fiction, “The Birdman” weaves together a story of three men, each of whom must leave to find meaning somewhere else. Three generations – a grandfather, a father and his son – face the urge to disappear and reinvent themselves, so that they can do the most genuine thing of all: change their very lives.