What lessons do the characters in "Good Country People" and "The Lesson" learn?

In the short story "Good Country People" by Flannery O'Connor, the characters, particularly Joy, are taught the lesson that their pride in their own knowledge has blinded them to the lessons that other people have to teach them. The visiting Bible salesman, Manly Pointer, is not really there to teach lessons from the Bible. He is there to earn money and to extract pleasure without any regard for the well-being of others. Because of her Ph.D., Joy thought that she was sophisticated and cynical and that he was ignorant and naive, but actually, she is the one who is naive. When Manley Pointer steals her prosthetic leg, he is symbolically stealing her artificial sense of security. It is unclear whether Joy actually learns the hard lesson that she is taught.
Similarly, in the short story "The Lesson" by Toni Cade Bambara, the protagonists inadvertently learn one lesson that is different from the lesson that was intended. At the beginning of the story, Sylvia, the protagonist, announces that “Back in the days when everyone was old and stupid or young and foolish and me and Sugar were the only ones just right." To be "just right" is not to be in need of lessons. But as it turns out, Sylvia needs to learn lessons just like everyone else. The lesson that she learns, however, is not the lesson that was intended by her would-be teacher, Miss Moore. The lesson that she learns is about injustice and the suffering caused by injustice.