David Gordon Green often casts locals in his movies. Gary Poulter was a homeless man in Austin. Poulter died on the streets of Austin on Feb. 19, 2013, 2 months after filming ended.
Nicolas Cage described his performance as naked saying that Joe character is very close to him and he didn't need to act.
According to Nicolas Cage, Joe is the closest character to him in real life.
Despite his financial problems Nicolas Cage turned down two big budget movies (I mercenari 3 (2014) and Killing Season (2013)) to prepare for the role.
Nic Cage tried and failed to convince director David Gordon Green that the movie should feature a scene in which his character is playing the pan flute naked in a backyard. But Green was at least open to Cage's reasoning, which reportedly involved the ancient Greek god Pan.