Samuel Ullman
Definition.com
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.
Definition.com
Youth is not a time of life-it is a state of mind; a temperamental predominance of courage over timidity, of the appetite for adventure over a life of ease.