Explain the situation involving Mrs. Dubose in Chapter 11? What lesson did Jem (and we) learn from her final days?

We learned how amazingly brave she was. Instead of living her last few days on her morphine addiction, we learn how she decided to die clean. Everyday the alarm clock went off a little later, signaling her weaning herself off and eventually breaking her addiction once and for all. Jem, who originally hated Mrs. Dubose for saying a lot of mean things about Atticus, forgives her and sees her bravery. After she dies, he takes the flower she left for him and "fingers it." His views on people change because he realizes that he doesn't know what struggles they could be facing.