He claims that the film is a study of friendship and based on a time when all he had in the world was his friends. He praises Christian Bale’s ability to learn Spanish and the L.A. street lingo used predominantly throughout the movie. Ayer talks about the street slang and how he used as much of it as possible for authenticity’s sake. He cites this film as a love letter to L.A. with lots of inside jokes and references that people born in the city would appreciate. To this end, he points out all the practical locations he used in the city.