Nobody grows old merely by living a number of years. We grow old by deserting our ideals. Years may wrinkle the skin, but to give up enthusiasm wrinkles the soul.
Old age, believe me, is a good and pleasant thing. It is true you are gently shouldered off the stage, but then you are given such a comfortable front stall as spectator.
Preparation for old age should begin not later than one's teens. A life which is empty of purpose until 65 will not suddenly become filled on retirement.