So how do I deal with this. I allow myself a long-list. Date, source, title. When I have finished a book, I scan the long-list and ask myself: what is the purpose, what is the outcome if I buy and read this book? Will the knowledge acquired contribute to my priorities? Does the book fit the circumstances under which I am considering reading it? When positive, it is entered on my short-list. Then I make a choice, rather intuitively.