Stepping back from Morrie's story, Mitch tells the reader that he looks back at who he was before he reconnected with Morrie, and he wishes he could talk to that person and offer him some advice. Mostly, he wants to tell him to get on a plane and visit Morrie, before Morrie gets ALS and can no longer dance. Mitch says he knows he can't do this, but if Morrie taught him anything, it's that there's no such thing as too late.
Mitch is wishing he could be the teacher for his younger self now that he's completed Morrie's final class. However, because of Morrie's lessons, Mitch knows he can't, but he also knows he can continue changing for the better in the future.
A short while after Morrie's death, Mitch is able to reach his brother in Spain and the two have a long talk. Mitch tells Peter that he just wants to be in touch, and that he loves him. A few days later, Mitch receives a faxed letter from Peter, consisting of a few stories of what he'd been up to that week, ending by sharing that he has heartburn and diarrhea, and signing off "sore tush." Mitch laughs until he cries.
This concludes the subplot of Mitch's relationship with Peter, and Morrie's teachings are clearly being applied. Mitch is finally able to meet Peter where he is, and simply tell him he loves him. The power of these words is reinforced when Peter then chooses to reach back out to Mitch.
Stepping away from the narrative again, Mitch goes back to provide some more information on the book. Mitch says it was mostly Morrie's idea, and that he called the book their “final thesis.” Morrie was excited that several publishers were interested, although he never got to meet any of them. However, the advance money paid some of Morrie's medical bills, which were enormous. Morrie enjoyed naming things, and while Mitch and Morrie were suggesting titles, Mitch suggested Tuesdays with Morrie. The title made Morrie blush.
Remember Morrie's prior insistence that he and Mitch continue to work on this project, even as he Morrie canceling other visitors. The fact that Morrie prioritizes his final thesis with Mitch over other engagements shows just how important teaching is to Morrie. Also note how philanthropic Mitch is with the money from the book—he's transformed for the better and is helping others, like Morrie would.
After Morrie's death, Mitchsays that he went through boxes of material from college and discovered a final paper from one of Morrie's classes. Mitch and Morrie had scribbled comments to each other on the front page, Mitch's beginning with, "dear coach," and Morrie's beginning with, "dear player." Mitch says that every time he reads those notes, he misses Morrie more.
Mitch is looking for more ways to experience and remember his relationship with Morrie. Using "coach" and "player" again shows how close Mitch and Morrie were, and again situates their relationship as a teaching/mentoring one.
Addressing the reader directly, Mitch asks if you've ever had a teacher who saw you as a raw, precious thing that could be polished with wisdom. He says that if you're lucky enough find such teachers, you'll always find your way back to them, whether it be in your head only or next to their bed.
This is the closing thought on the idea of teaching and the importance of teachers. It reinforces the idea of teaching as a cyclical relationship that students come back to, rather than just the one-way transfer of knowledge.
The last class of Morrie's life took place once a week on Tuesdays, next to a window where Morrie could watch his hibiscus plant. No books were required, and the subject was the meaning of life, taught from experience. Mitch says, finally, that the teaching goes on.
By reiterating the opening words of the book, Mitch brings its themes full circle. This mirrors the final idea that the teaching goes on—the reader has now completed the class and can go on to teach others.