* AbilityOverAppearance: Joaquin Phoneix is 5"8, making him six inches shorter than Johnny Cash, but he plays the role brilliantly all the same. It helps that he was chosen by the man himself for it.
* ActorAllusion: Music/WaylonJennings is played in the movie by his son, Shooter.
* RealLifeRelative: Shooter Jennings is the son of Music/WaylonJennings. He even performed his father's song, "I'm A Long Way From Home".
* ThrowItIn: In a scene portraying Cash under the influence of drugs, Phoenix grabbed hold of a sink and ripped it out of the wall. This action was not in the script.