To Kill a Mockingbird is a coming of age novel, with both Jem and Scout learning much through their experiences with Boo and through their father's defense of and the town's reaction to Tom Robinson. Jem also learns from his experiences reading to Mrs. Dubose, although that happens only after Atticus explains to him that he must not lose his temper in a violent way, that he must be kind to people who are not kind to him, and that the mean old lady whom he hated so much was in fact, as Atticus tells him quite clearly, a brave woman. "I wanted you to see what real courage is, instead of getting the idea that courage is a man with a gun in his hand. It's when you know you're licked before you begin but you begin anyway and you see it through no matter what." Mrs. Dubose decided to cure herself of her drug addiction before she died, and did. similarly, Atticus knows he is doomed to lose in defending Tom, but he defends him anyway, facing overwhelming odds. It is the facing the impossible that makes him victorious. Through both the incident of a cantankerous old woman and his father's convictions concerning Tom, Jem learns what heroism and character mean.
After Jem and Scout returned home after the fire at Miss Maudie's place was put out, they only realised that Scout was clutching a blanket when Atticus brought it to their attention.
That was when they knew that Boo Radley was the kind soul who attempted to keep Scout warm.
Jem then realised that he had wrongly judged Boo and learns that he should not be prejudiced and to make judgements based on his own experiences and not simply forming his own conclusions based on wild rumours and gossips.