After watching the movie, Walk the Line, I was most interested to see how true the movie was to the real life of Johnny Cash. I do remember hearing on NPR when the movie came out that the producers/directors had long conversations with June and John, and that they stressed that the movie had to be honest - even about how their relationship started.
If you're looking for that type of honesty, it's not in here. That is not to say that the book lies, it just glosses over these bad parts. There is much in here that was not in the movie however. In this book, John constantly refers to his religion and Jesus. This was an aspect of his life that was not covered in much detail in the movie. I had no idea that John was so religious.
One thing that I did like about the book is the lack of preaching. Even with all the references to Jesus and Satan, I never felt that I was being lectured. I am not Christian and when I read a book with a religious slant, I find that the author usually is trying to recruit through the book. Which is a turn off. Not here - John just lays out his path, his trials and how he came back to Jesus. And how he still struggles every day with Satan.
I really did like this book and I'm looking forward to reading his 2nd biography which was written about 20 years later. When he wrote this book, he was in his 40's. It will be interesting to see how those additional 20 years or so add to his experiences of life.