In the book "Fangirl" by Rainbow Rowell, there is a quote that says “It’s just... everything. There are too many people. And I don’t fit in. I don’t know how to be. Nothing that I’m good at is the sort of thing that matters there. Being smart doesn't matter—and being good with words. And when those things do matter, it’s only because people want something from me. Not because they want me.” Cath is so used to just being used that she doesn't even know when they actually need her or when they're using her. She thinks that she's not good enough to be around anyone which falls back into the theme of isolation. She would rather be isolated than to make a fool out of herself in front of people. She feels like an outcast, like she is so different from everyone else. That's why she hides behind her laptop and writes her fanfiction, because when she writes she changes into a different person. No one judges her because they all like to read her fanfiction, in the world of the Simon Snow fans they are all have a similar taste.