Youth is not a time of life; it is a state of mind; it is not a matter of rosy cheeks, red lips and supple knees; it is a matter of the will, quality of the imagination, a vigor of the emotions; it is the freshness of the deep springs of life.
In the central place of every heart, there is a recording chamber; so long as it receives messages of beauty, hope, cheer and courage, you are young.
When the wires are all down and your heart is covered with the snows of pessimism and the ice of cynicism, then, and only then, have you grown old.
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.