Back to front

I saw a woman reading a book on the subway today and the book's chapters were numbered back to front: she was close to the end of the book and she was starting on chapter 3.

Was that just different to be different or was it a legitimate way to work a narrative towards it's conclusion while giving you a sense of the path ahead? Whichever it was, it kind of blew my fucking mind and I wish I had a way to flip my life around like that. Make it different and make it work towards something.