I really didn't like John when I started this book. He was self absorbed and arrogant, you only ever hear about other people in how they relate directly to him. And then there are moments like when he was talking about Mary: 
 "I knew I wanted to experiment with different girls, and I didn't want to ruin things with her. I was saving her for when I felt like I could be more faithful, saving her for when I thought it might last." 
 I suppose it's a noble attitude to a point but the way he spoke like girls were tools to be used at his leisure was not a flattering personality trait. 
 Then there was his sexuality. This didn't have a large baring on whether I liked him or not, I just found it odd. I've personally never met anyone who claimed to be entirely 100% straight except for one guy and really meant it. I figured it might be him just trying to work out his sexuality, but it's not like he was afraid to be gay, so it was all a little perplexing. The thing is, John's struggles with his sexuality weren't really a major part of the book. They are a major part of him coming to terms with himself but there were more important things at play which weren't revealed until later on in the book. 
 It wasn't until John started talking about his guilt around what happened to one of the friends he had as a child, Berry where I began to see another side to him. It's not so much that he believes the arrogant things he tells the reader, it's more that if he doesn't force himself to believe it, he'll be forced to accept responsiblity for some horrible things that have taken place around him. 
 It was an interesting approach to portray the narrator as an arrogant douche only to rip that down and show the vulnerable underbelly, wracked with guilt and self loathing. I began to think that perhaps he treated the girls like objects to be discarded because that's how he believed he should be treated. 
 By the end of the book, I liked John a lot more because I understood him a little better. I think Nathan could have used more development, but since the story is told from John's point of view it makes sense that everyone else is a secondary character to what's going on in John's head. 
 I've been reading a lot of LGBT coming of age books recently and thought this was going to be similiar. It's really not, it's about a kind coming to terms with himself, but the content becomes a lot darker after the halfway point. I wasn't expecting that, but it added a much needed depth to the book and to John in particular.