Time marches on with a certain relentlessness. I don't feel older but I am. I look around me at work and I'm old enough to be most people's mom. Yet inside me, I still feel young and vital. When I look in a mirror, I remember that I am not young but that I am still vital.
Age allows you a certain perspective. Truths that you really believed were true and turning out to be not so certain. Things "set in stone" are found to really be set in shifting sand.