... no one ever became excellent in any exercise whatsoever without beginning from his childhood to endure heat, cold, hunger, thirst, and other discomforts; wherefore those men are entirely deceived who think to be able, at their ease and with all the comforts of the world, to attain an honorable rank. It is not by sleeping but by waking and studying continually that progress is made. [on Luca Della Robbia].