Sorrow floats. - John Irving

...friends were more important than lovers - not least for the fact that friendships generally lasted longer than relationships.

I can't imagine what the first sentence is, I can't imagine where I want the reader to enter the story, if I don't know where the reader is going to leave the story. So once I know what the last thing the reader hears is, I can work my way backward, like following a roadmap in reverse.

We don't always have a choice how we get to know one another. Sometimes, people fall into our lives cleanly-as if out of the sky, or as if there were a direct flight from Heaven to Earth-the same sudden way we lose people, who once seemed they would always be part of our lives.