Strangers on a train
I've been told so many times that no one talks to anyone on a subway. This has not been the case for me. People talk to me all the time on the subway, sometimes to ask for directions (a challenge, having never lived in New York), and sometimes just to talk. One of my favorite movies, Before Sunrise, involves two people meeting on a train and taking a leap of faith, which was also in the back of my mind when I wrote my book.
Subway chatter is a major thing in Lullaby, both for the main characters, Kate and Ethan, and the characters they portray in Ethan's play, Anna and Jack, who really do meet on a train. There's something so romantic about that idea, isn't there? That you could meet someone special in such a normal and even anti-social place. People on trains are caught together in the in-between - on their way to work, to a funeral or wedding, to their apartment after a breakup, to a bar for a first date. Headphones are in, eyes are closed, but once in a while, every so often, you notice someone, and maybe they notice you.
So because people have never been shy about talking to me on trains, and because the idea is so romantic to me, I decided it wasn't implausible that two people could meet and even flirt on a subway. And I'm so glad I stuck with it, because the train has become such a symbolic part of my novel and really in my own life, too.