Give me the boy who rouses when he is praised, who profits when he is encouraged and who cries when he is defeated. Such a boy will be fired by ambition; he will be stung by reproach, and animated by preference; never shall I apprehend any bad consequences from idleness in such a boy.
QuintilianOur minds are like our stomaches; they are whetted by the change of their food, and variety supplies both with fresh appetite.
Quintilian