This was another YA novel doing a sort of memoir of a character – in this case Obi Wan Kenobi. The set up is that he left a journal in his cave on Tatooine and Luke found it when he went back to rescue Han Solo from Jabba the Hutt.
I didn’t learn a whole lot here. It seems that Luke had only met Ben twice before in his life before the droids landed on Tatooine. And there is a strong sense of remorse in his assumption that Anakin was irredeemable. Bot mostly, this book pulled together the mythology from the films and a bunch of the novels and printed it in one place. I guess there is some value to that.