In bad situations, it can help to imagine the world to be the way you want it to be. However, there's a danger of going too far; instead of simply having goals, you can become delusional. In The Girl on the Train, Rachel lives in a world of pure imagination. But hers is a lot darker than a candy-colored Willy Wonka wonderland. She imagines that other people have what she herself has lost and ends up making herself feel worse in the process.
Questions About Versions of Reality
Rachel imagines a life for Megan and Scott as "Jess and Jason." Why does she create their lives the way she does? Where does she get her inspiration? Is she correct about any of her assumptions?
When Rachel meets Scott, how long does she still treat him like "Jason"? When does she realize he's a different person? When does she realize Megan is not "Jess"?
How has Rachel altered her own life? When does she realize her life with Tom was a lie? How did/does Tom manipulate the truth?
Chew on This
Rachel only sees Scott and Megan in their happy moments, so she creates a perfect life for them in her imagination. Many people do something similar when looking at friends' Facebook photos.
Rachel creates a fantasy life for "Jess and Jason" based on her own failed marriage. She eventually learns that she can't have her perfect marriage back, mainly because it never was perfect to begin with.