"When Howard Marks came out of prison, years later, I met him at a concert in South Wales; I was a young whippersnapper and Howard was kind of an outlaw hero. I said to him - and it's on tape, a cousin of his filmed our meeting - I said, "If you write a book, I want to play you in a movie." He said, "Let's shake on it," and we did. Thirteen years later, there we were, making the movie."