"Old age isn't a battle. Old age is a massacre."-- Philip Roth, Everyman (2006).
I am reading Philip Roth's most recent novel, Nemesis, and was sad to learn that it is his last. At age 78, he has stopped writing. He's had enough.
I haven't had enough though. I have read almost every Philip Roth book that's been published, fiction and non-fiction, and he's been one of my favorite writers for a long time. You may know some of his writings -- American Pastoral, The Human Stain, Portnoy's Complaint, and many more... Some of his more recent books have dealt with aging and how helpless we are to stop the physical and mental agonies of the aging process.
He can retire satisfied with his accomplishments, but I'll selfishly miss his future works.