I picked up From Strength to Strength after hearing about it on a podcast. It is a great perspective on the reality of ageing. You have certain qualities that are better when you are younger. Clearly strength, speed, power those physical characteristics degrade as we age. So too do certain mental qualities. You can try to fight this or you can accept it and open yourself up to the things that can get better with age. Work with reality rather than against it. Like most of these books though, they are always way longer than they need to be. You turn a great essay into a good book.