As I have just become eligible for Medicare, I remember that while I can't stop aging, I can choose not to grow old.
            

Oliver Wendell Holmes spent thirty years on the bench of the U.S. Supreme Court, retiring only after he turned 90.  He credits his endurance in such a serious job to having maintained his youthful playfulness.  We don’t need to give up the good things about childhood when we grow into old age.