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.
Despite his financial problems Nicolas Cage turned down two big budget movies (The Expendables 3 (2014) and Killing Season (2013)) to prepare for the role.
According to Nicolas Cage, Joe is the closest character to him in real life.
Both actors Nicolas Cage & Tye Sheridan have starred in Marvel Comics films. Cage starred as Johnny Blaze / Ghost Rider in Ghost Rider (2007) and Ghost Rider: Spirit of Vengeance (2011). Sheridan starred as Scott Summers / Cyclops in X-Men: Apocalypse (2016) and Dark Phoenix (2019).