Brain Snacks: Tasty Tidbits of Knowledge
The Girl on the Train is the first novel by Paula Hawkins. Sort of. See, prior to publishing The Girl on the Train, Paula Hawkins (if that is even her real name) published four romantic fiction novels under the pseudonym Amy Silver. (Source)
One of Tom's favorite lines to use on his gullible ladies is "Don't expect me to be sane." Rachel calls him out, revealing that he stole the line from surrealist author Henry Miller. The line didn't appear in any of Miller's explicit novels, like Tropic of Cancer; he wrote it in a real-life love letter to Anaïs Nin. Both authors were married during this correspondence, making it an even more appropriate line for the adulterous Tom. (Source)
While Paula Hawkins is flattered by the comparison of The Girl on the Train to Gone Girl, she's not sure it would be made if she and Gillian Flynn weren't both women. (Source)