How did John changed in the book (chapter 10-12)

In Chapters 10-12, we see John mature. He and Lorraine decide that Mr. Pignati needs know the truth, and they reveal their lies. John also has gained the maturity to call for help when Mr. Pignati collapses and to care for his house while he is hospitalized. Unfortunately, John doesn't mature enough to realize throwing a party in someone else's home could lead to trouble.... he still has a lot to learn.