Photograph your bookshelves. Then, make a list of every book that’s on the shelves, putting a check mark next to the books that you’ve actually read.
Next, make a list of all the books that aren’t on the shelves that you’ve read over the years. Some you’ll have no problem remembering, others you won’t be able to recall. And then make still another list, this one noting all the books you want to read but haven’t — yet.
Update frequently, and keep the lists and photographs tucked away in your favorite book.