When I started to write this book and I was writing and writing every day, then when that darkness came, I was ready to enter it. It took time before that, to reach that stage. You can't do that by starting to write today and then tomorrow entering that kind of world. You have to endure and labor every day. You have to have the ability to concentrate. I think that's the most important ingredient to the writer. For that I was training every day. Physical power is essential. Many authors don't respect that. [Laughs] They drink too much and smoke too much. I don't criticize them, but to me, strength is critical. People don't believe that I'm a writer because I'm jogging and swimming every day. They say, "He's not a writer."

-Murakami