What is a major theme in the story?

Consider the them of fact vs fiction. Within this novel there are many instances where the reader, and Ted, isn't always certain of the validity and reality of a situation or event. Angela, in particular, gives him false information on more than one occasion, to the point that he doesn't always believe what she tells him. She tells him that her father is her stepfather, when in reality the man that comes to parent's day is in fact her father. The story that she writes about her father dying when she was young (like Ted's) is a complete fabrication.