How would you tell the difference between a book that has your life story in it and a similar book with inaccuracies in all the details you don't remember?
The book qualifies this by giving everyone a perfect memory of every moment of their lives.
> I found I could recall every detail of my life; every event ever experienced I could remember with perfect clarity. I could remember every word on every page I'd ever read. Every conversation. Every tax form I'd ever filled out. I could reconstruct every second of every day I'd been alive from the moment of my birth until the day I finally shut my eyes at the end.
> This clarity of memory surprised me the first time I tried reviewing the past, but it was all there. (This was to be the greatest curse of Hell. Sometimes I would reply my entire life again and again for thousands of years. Remembering all the things I could have done differently, all the things... No. I won't go there now. I must tell this story).
To paraphrase The Incredibles: when every book is there, no book is there.