When Calpurnia takes Scout and Jem to her church, this is the first time Scout really considers Cal's life beyond the Finch household. Scout marvels that this had never occurred to her.
That Calpurnia led a modest double life never dawned on me. The idea that she had a separate existence outside our household was a novel one, to say nothing of her having command of two languages.
Scout also notices that Cal speaks differently around black folks than she does around white folks. Scout learns that there are cultural differences between the two which makes Cal's "double life" that much more interesting. This was a good learning experience for Scout because she learns some of the cultural differences of the racial divide in Maycomb.
One of the biggest lessons in the book is learning to see things from the perspective of others. Atticus is the perfect role model to teach such lessons. He even considers the perspective of people like Bob and Mayella Ewell. When Bob spits in his face at the post office, he says that he'd take that any day if it saves Mayella an extra beating. (Chapter 23)
Jem, Dill, and Scout had their minds made up about Mrs. Dubose, Mr. Avery, and Boo Radley. It turns out that they never considered there might be more to these people than rumors and what they saw on the surface. Mrs. Dubose was brave, Mr. Avery helped Miss Maudie when her house caught fire, and Boo saved the children from Bob Ewell. At the end of the novel, Scout considers this lesson, literally viewing another perspective of the town from the vantage point of Boo's porch:
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.