Youth is not just a stage 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, a quality of the imagination，a vigor of the emotions.

It is the freshness of the deep spring of life.

Youth means the predominance over of courage over timidity, of adventure over the love of ease.

This often exists in a man of sixty more than in a boy of twenty.

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.

Worry，doubt，self-distrust，fear and despair - these bow the head and turn the growing spirit back to dust.

Whether sixty or sixteen，there is in every numan being's heart the love of wonder, the sweet amazement of the stars and the starlike things, the undaunted challenge of events，the unfailing  childlike appetite for what-next and the joy of the game of living.

You are as young as your faith，as old as your doubt, as young as your self-confidence, as old as your fear, as young as your hope, as old as your despair.