The 48-year-old actor's new movie The Rum Diary has proved a flop at the US box office since its release but he insists he never worries about his movies making a lot of money and he thinks the film will stand the test of time.
He said: "It's always a c**p shoot and really if you have that in your head while you're making a movie the process would become something very different. No, I couldn't give a rat's arse [about the money), not really.
"I believe that this film, regardless of what it makes in, you know, Wichita, Kansas, this week - which is probably about $13 - it doesn't make any difference.
"I believe that this film will have a shelf life. I think it will stick around and people will watch it and enjoy it."
Johnny also believes the film - which is based on the semi-biographical book of the same name by gonzo journalist Hunter S. Thompson - will "most definitely" be a bigger hit in Europe because it is too "intelligent" for American audiences.