The Novel According to Irving
When Irving began the novel, he wrote, "In the world according to Garp, we are all terminal cases." He thought he was writing the first line of the novel. Then he realized it worked better as an end to the first chapter.
"First I thought it was the first chapter, then the second, then it slowly made it's way through the novel until I finally realized it was the end." The line, of course, ended up as the last line of the book.
Since Garp, Irving always hones in on the last line before writing the rest of the novel. "That makes it as if the story already happened to me. I already know what I need to say and only need to focus on how to say it -- the language and structure and tone."
Do all authors agree? Only a terminal case would think so. Get another point-of-view from another established novelist in the next installment of Writeful.