“One of the vital things for a writer who’s writing a book, which is a lengthy project and is going to take about a year, is how to keep the momentum going. It is the same with a young person writing an essay. They have got to write four or five or six pages. But when you are writing it for a year, you go away and you have to come back. I never come back to a blank page; I always finish about halfway through. To be confronted with a blank page is not very nice. But Hemingway, a great American writer, taught me the finest trick when you are doing a long book, which is, he simply said in his own words, “When you are going good, stop writing.” And that means that if everything’s going well and you know exactly where the end of…