In “Why We Write,” edited by Meredith Maran, author and Globe contributor, 20 famous writers take us inside their literary worlds to see how the magic of writing takes place and to explain why otherwise sane people would engage in an activity that, Maran argues, “promises only poverty, rejection, and self-doubt.”

First, the mystery of creation. For novelist Isabel Allende, stories begin inside her and then grow onto the page: “Each story is a seed,” she explains, “that starts to grow and grow. . . . When I start writing a book, I have no idea where it’s going.” Like many of the writers here, Allende says she has difficulty separating her real life from the lives of her fictional characters. “I carry the story with me all day, all night, in dreams, all the time,” she says.