Tomorrow, and Tomorrow, and Tomorrow - Gabrielle Zevin

This is the story of Sam and Sadie. It's not a romance, but it is about love. When Sam catches sight of Sadie at a crowded train station one winter morning he is catapulted back to the brief time they spent playing together as children. Their unique spark is instantly reignited. What comes next is a story of friendship and rivalry, fame and creativity, betrayal and tragedy, perfect worlds and imperfect ones. And, ultimately, our need to connect: to be loved and to love.