Character Development: A Walk to Remember

I am nearing the end of my book which is actually upsetting because i really liked it. However for the character Jamie, and unexpected turn happened in her life last summer that the reader is just now finding out about. I can't give too much information away without ruining the book but this plot twist has made this book hard to put down.Over the course of the book the main character Landon Carter has made some biggest character changes. At first he was a jerk. All he cared about was what people thought of him and trying to be cool. Now at the end he is a much bigger person. Eventually he asks Jamie out but it took him awhile to get over himself. Also he used to be embarrassed to be seen with her which is very shallow in my opinion. Now he could care less about what people think about him. He is OBSESSED with Jamie, he told her that he loved her and will do anything for her. He lost a lot of his friends because to them he changed for the worst. Now Jamie has revealed her well kept secret to Landon and it has totally affected him. However this has made him more understanding and patient in my opinion but you can also tell that he is scared for Jamie. He is trying to find a way to fix things which shows how much more determined he has become but he doesn't understand... Some things just can't be fixed.