Chester ends the book by talking about the publication of Code Talker, and he says that his big hope is that the book will "keep the memory of the code talkers alive." (23.4). (Thankfully, by reading Code Talker, you're doing just that. Well done, Shmooper.)
He also tells us that even though his health his failing (he's had two legs amputated because of complications from diabetes), he still travels to do book signings and give speeches. He tells us that he still travels with his medicine bag in his pocket—like the one that he kept with him during the war in the Pacific, to keep him safe. His last words are "It's been a good life—so far" (23.7).
This ending provides closure for us readers in a number of ways. First of all, it tells us what Chester's been up to since writing the book. He's still going strong, sharing the story of the code talkers, despite his bad health. (We know that Chester Nez died in 2014, at the ripe old age of 93. Rest in peace, Chester.)
The reference to his medicine bag is also important because it shows us that, even in his old age, Chester is still very closely connected to his Navajo culture. This culture is at the center of his identity. Finally, his statement that "It's been a good life—so far" reflects his very optimistic outlook. We've mentioned that the narrative tone of this book is defined by optimism. Chester has lived through some tough times: the Great Livestock Massacre that destroyed his family's livestock, very traumatic experiences in World War II, the death of three children, and a divorce. But he still says that he's had a good life.
Don't we wish we were all as optimistic and positive as this guy?