Ecclesiastes 1:18

Labour. He is bound to do more for heaven, as he is convinced of his own defects, and of the strict judgments of God. Wisdom is not true happiness, but the means to obtain it. (Worthington) --- The more a person knows, the more he is convinced of his own ignorance, (Calmet) and filled with grief, that wisdom should be so much concealed. (St. Jerome) --- Those who are learned, feel indignant that their disciples should be so dull. (Menochius)