My book group wanted a novel. They like to alternate between fiction and non-fiction and we had just discussed "The Invention of Nature: Alexander von Humboldt's New World" by Andrea Wulf. So, it was time for fiction. The first such book that came to my mind was "Skinwalkers" by Tony Hillerman. I had read it aloud to Lynn sometime in the last 50 years. I remembered the title referred to Navaho evil witches and that I had liked the book. Other men liked the suggestion. Since it had been so long since I read it, we are reading it again.
When older people return to a book they read and enjoyed long ago, all sorts of memories get involved. You remember the story, the atmosphere, the setting. You may remember what didn't like or have since developed a distaste for. Re-reading and re-watching can be quite eye-opening.
Experiences of re-reading can be launched with the help of a list of books that you remember. It doesn't have to be complete. The books listed don't need to have been read completely. It can be fine if "The Family of Man" (almost totally photographs) or a Calvin and Hobbes book of cartoons is included. When experienced adults make a list of books, I think it works well to start using just one's memory. If you can list 3 books, or 3000, it doesn't mean that you are good or bad depending on the number of books. If you can remember only "The Story of O" and "Fifty Shades of Grey", it doesn't mean you are a sex maniac or a bad person.
After listing some books, whenever you feel like it, you can take a moment to think back to see what you remember about the book, about yourself at the time you read it. If you can find a copy or download one, you may want to look through it to get an idea of your current reaction to the text and to the earlier experience of reading the book.
Here is a link to a list of 300 books that have mattered to me.
https://fearfunandfiloz.blogspot.com/2008/04/kirby-1983-reading-list-of-good-books-i.html You can see that it is rather old.
After making or finding a list of some books you found good or moving or helpful, this list may remind you of additions you could make. My friends discussed "Skinwalkers" the other day and many fond memories came to their minds. One professor who is a fan of the state of New Mexico, made a map of the locations of main Skinwalkers events. We have been having fun remembering other impressive books, like The Once and Future King by T.H. White and negative impressions from The Wings of the Dove and Moby Dick.
Similar memories may come with reviewing movies that mattered.