You learn to do research. You develop the confidence to ask strangers about topics you know nothing about. When I wrote Festival in Fire Season, about people who get caught in a huge wildfire, four different firemen helped me. I wouldn't have been able to write it without them, and without my journalism background, I wouldn't have had the nerve to ask. I still write some nonfiction.
Most writers do.
But fiction is my first love. She gets paid a lot of money. She sells all kinds of rights that may not have been sold before. The book gets a new life. I thought Susan Sarandon was wonderful.