By the end of the book, the children finally understand the wisdom inherent in all the moral lessons Atticus has ever tried to teach them. When the repulsive Bob Ewell attacks the children as they walk home from a school pageant, Scout and Jem are saved from certain death by their elusive neighbor, Boo Radley. It is Boo who carries Jem home after he (Boo) fatally injures Bob Ewell in the children's defense. Jem's left arm is broken and he has sustained a slight injury on one side of his face, but Dr. Reynolds tells Atticus that Jem will recover from his frightening experience.
When Scout notices that Boo is in their house waiting for news of Jem's prognosis, she feels suddenly shy and embarrassed. She remembers every game she participated in with Dill and Jem to get Boo to venture out of his house to talk to them. In these reminiscences, she suddenly realizes that the never really understood Boo. When Boo ventures to bid goodnight to the unconscious Jem, Scout comes to see how much he cares about them. She walks Boo home and realizes how wise her father has always been:
Atticus was right. One time he said you never really know a man until you stand in his shoes and walk around in them. Just standing on the Radley porch was enough.
Atticus, he was real nice...Most people are, Scout, when you finally see them.
From the gifts Boo left in the tree to his selfless defense of the children's lives, the introverted Boo has quietly watched over the children for a long time. He turns out to be someone who hardly resembles the scary monstrosity the children have built him up (in their minds) to be. Thus, when Scout looks back at all their efforts to draw Boo out of hiding, she realizes that they never took into consideration the type of person their rescuer really was. Sheriff Tate asserts to Atticus that exposing such a shy, retiring individual to undue attention for his role in Bob Ewell's death would be a sin. Scout agrees, finally understanding that exposing Boo Radley would be like shooting a mockingbird, hurting an innocent whose sole purpose in life is to bring others joy and comfort.
In the end, Scout realizes how dependable the wisdom of her father has always been. It is as dependable as his love for them.
He turned out the light and went into Jem’s room. He would be there all night, and he would be there when Jem waked up in the morning.