One big life issue that John faces throughout the book is how to deal with drugs and alcohol. John smokes a lot through the book, which is a concern of mine, but I feel that his alcohol drinking is a larger, more immediate concern. I feel that a reason that many teenagers drink is to defy their parents, but that is not the case with John. His dad actively encourages him to drink and thinks it's funny that his son is going to be a future alcoholic. John doesn't see much issue with it either.
“That kid’s going to be a real drinker,” he’d say in front of company, and then I’d go through my beer-drinking performance for everybody, and they’d laugh their heads off. It was about the only thing I ever did that got any attention.
Another major issue that John (and Lorraine) deals with is family relationships. John's home life is miserable. He can't stand his father. John calls him "the bore." Being around his parents is an emotionally empty place to be. His parents do not encourage his passions and dreams. Instead, they try to push John toward a career path that he wants nothing to do with. On top of that, they constantly compare John to his older "perfect" brother. The entire situation makes John feel more and more worthless. He has the overall impression that he is wasting his parents' time.
A third big life idea in John's life is the presence of death. There's a lot of it in this book. Mr. Pignati dies, his wife is dead, Bobo dies, Lorraine's mother takes advantage of dying patients, and John's dad might die because of his over drinking. Most teenagers feel that they are invincible and will live forever, but John and Lorraine are surrounded by constant reminders of human mortality.