If I were going to teach fiction in the future, I would use this book as a main source for the class. This is exactly the type of thing young writers (and seasoned ones) need when they're working on character development. A lot happens in the story, the two characters travel Europe, but that's not at all the focus. The characterization is just brilliant, Zipper and her husband are lovable and human and real.
The twist at the end, spoiler alert, was well done and not cheesy. Zipper writing what her husband would be doing makes exact sense when she's been carrying around that blank journal. I love that the first and the end lines match, the literary symmetry fit so perfectly without being overdone. Richardson's language is simple but eloquent, he doesn't need six clauses in a sentence to get his point across.
Oh. And I missed the quotation marks for dialogue badly. But that's just me being curmudgeonly.