I did not think I was going to finish this story tonight, but the last 1/3 of the book completely drew me in to full on reading mode. 
 I think a lot of the negative reviews stem from thinking this was a school shooter type book, but I wouldn't compare it. Leonard is just committing murder-suicide (view spoiler)[and not even at school. 
 The only thing that relates to school is the fact that he goes to school and he brings the gun to school, but doesn't have any actual plans of shooting up the school! (hide spoiler)] 
 So not comparing him to Eric Harris and Dylan Klebold; this is a great story! 
 I hated Leonard at the beginning. I didn't understand his problems, why he acted the way he did, I just thought he was purely selfish. My God, who cares if everyone forgot your birthday when they didn't even know when your stupid birthday was! 
 By the end of the book, I ended up crying for Leonard and absolutely adoring Herr(but secretly hating the name). 
 I think the story developed beautifully, I just wish I would have ended the book with a better feeling of knowing how it ended. How everyone turned out to be.