Slaughterhouse Five- parallelism

"He got a few paragraphs into it, and then he realized that he had read it before- years ago, in the veterans' hospital.  It was about an Earthling man and woman who were kidnapped by extra-terrestrials." PAGE 201

This quote provides parallelism between the plot of the book and one of the destinations of Billy's time traveling experience.  Billy travels to a planet after being kidnapped by the extra-terrestrials.  He claims all of this happened, but he has no proof.  There is a parallel scenario between the one in the book and the adventure of Billy.  In the book, and in Billy's adventure, the Earthling is taken to another planet and placed in a zoo for observation.  In both scenarios, the Earthlings are watched carefully by the native inhabitants.  This parallelism allowed me to realize that Billy might not have gone to Tralfamadore.  He might have just thought he did because of what he read.  He might have envisioned or imagined the experience rather than living it.  He did not think he read the book before, but then remembers he did.  I think that he created the time travel illusion and Tralfamadore from this book.