Youth is not a time of life—it is a state of mind. It is not a matter of red cheeks, red lips and supple knees. It is a temper of the will; a quality of the imagination; a vigor of the emotions; it is a freshness of the deep springs of life. Youth means a tempermental predominance of courage over timidity, of the appetite for adventure over a life of ease. This often exists in a man of fifty, more than in a boy of twenty. Nobody grows old by merely living a number of years; people grow old by deserting their ideals.