To get into the mood of writing a surrealistic drama/mystery, Nicholas Zebrun watched the entire Twin Peaks (1990) series in a week long marathon. To further get into the mindset, he'd only write the screenplay after midnight, alone, in a dark room.
Originally conceived as a sequel to Block (2009). In that version, the character of Michael would be chased by the forces of death (personified by the Gentleman from Block (2009)) and an angelic force (which later became the character of Leah).
The trivia item below may give away important plot points.
The original ending was vastly different. In that version, the homeless version of Michael, who cradles the picture of Leah, begins mumbling her name over and over again. He is then awoken by Leah, in their home, asking if he's going to bed soon. He responds that he will but first must write something down. He then turns to his computer and begins writing the story for the film. This ending was rejected for being too cliché.