How does the reader benifit from Scout telling the story about Mrs. Dubose as an adult looking back at her childhood?

The events of Chapter 11 help underscore the severe racial intolerance of many of the townspeople, and the extreme ostracizing the Finches undergo in the name of maintaining good conscience. Mrs. Dubose calls all black people "trash" without exception, and tests Jem's patience. Atticus wants the children to understand that courage has to do with the fight for one's personal goals, no matter what the odds are against achieving the goal. Heroism consists of the fight itself, the struggle against fate, circumstance, or any other overpowering force. Mrs. Dubose's goal is to break free from her addiction to morphine. Her struggle against the clock and mortality is easily compared to Atticus's struggle to uphold his own morals despite the hopelessness of his case and the lack of support he has in town. According to Atticus's definition, he and Mrs. Dubose are both brave, even heroic, and he wants the children to follow their example. Even though Mrs. Dubose is a mean and bigoted old woman, she does have good qualities that demand respect. Atticus wants the children to see that though many of the townspeople are ignorant and racist, they also have personal strengths and are not fundamentally bad people.

Jem learns some lessons on how to remain impassive even when his father's judgment is questioned and criticized. Jem is usually calmer and quieter than Scout, but his outward calm often disguises as much hurt and anger as Scout feels and expresses. Because he so rarely expresses his rage in verbal or physical fights, he often ends up bottling his feelings up. When these feelings explode, as when he cuts up Mrs. Dubose's flowers, the explosion is much bigger and more destructive than anything Scout would normally do, and he finds himself extremely ashamed afterwards. Part of Scout and Jem's growing up consists of understanding how to manage their feelings of anger. Scout must learn to calm her responses, whereas Jem may need to learn to find useful ways to express his feelings rather than suppress them.