Christian Bale on his transformation into Patrick Bateman for American Psycho (2000)
The character is so vain and obsessed with his looks. While the psychology of the character was something that I could perform, you can't fake the physicality. Being English, I tend to enjoy going down to the pub far more than going to the gym, so it was very unnatural for me. I just had to convince myself that I loved it, which was the most difficult thing about playing this part. Working out is incredibly boring.
I swear it's true that the bigger your muscles get, the fewer brain cells you have. I found I had to stop thinking when I was in the gym because if I thought about it, I'd realize how ridiculous it was that I was pumping iron when I could've been out having a drink and a cigarette and enjoying some lunch. I did three hours a day for six weeks with a personal trainer and some time before that. I ate an awful lot during training and then almost nothing during filming.