I suggested a book to my book group. Another member asked if we hadn't already read that book. That we can't quickly tell by memory or by records if we have or have not read the book seems quite interesting to me.
As a young man, I enjoyed books by C.S. Lewis and Jacques Barzun. C.S. Lewis was a professor of literature at Cambridge University in England and he is the person that I know of who most ardently advocates re-reading. In fact, I think somewhere in his writings, he says that one should only read books that can be seen as worth re-reading. A retired professor of science recently stated an opposite case. He said that there are so many excellent books that it is better to read something else and not read a book over again.
I taught a graduate course in which we tried, as mature people, to list every book we have read, for fun and curiosity or for school requirements or whatever. It seems to be a natural progression for many people to recall a book that is remembered as a source of pleasure or valuable insight. To me, the next step might be to find a copy of that book and read it again to see how it feels later in life.
I have two book lists in my blog:
1983 https://fearfunandfiloz.blogspot.com/2008/04/kirby-1983-reading-list-of-good-books-i.html
2011
https://sites.google.com/view/kirbyvariety1/recent-reading-2011
These lists are books that I read. Today, I tried to select one that I thought of with pleasure, get a copy and read it. The first one I tried was "The House of Intellect" by Jacque Barzun (1959). He was born in France to a well-off, fairly high-ranking family and grew up among intellectuals. I couldn't find a copy within my low price range. I tried with "The Scarlet Letter" by Nathaniel Hawthorne, a book I had to read in high school and one I enjoyed.
I now have a copy but after looking it over, I may fail to read it again.