Basic Requirements of Graceful Aging

What I’ve discovered is that there are three “basic requirements” of graceful aging. To borrow from the “Serenity Prayer”, graceful aging requires the “serenity to accept the things we cannot change; courage to change the things we can; and wisdom to know the difference.” Certainly acceptance of aging is a key to aging gracefully – but which of the changes that commonly come with age are the “things we cannot change” and which are the “things we can change?”