Keep the extent of your abilities unknown. The wise person does not allow his knowledge and abilities to be sounded to the bottom, if he desires to be honored by all. He allows you to know him but not to comprehend him. No one must know the extent of a wise person's abilities, lest he be disappointed. No one should ever have the opportunity to fathom him entirely. For guesses and doubts about the extent of his talents arouse more veneration than accurate knowledge of them, be they ever so great.

THE ART OF WORLDLY WISDOM BY BALTHASAR GRACIAN
TRANSLATED BY JOSEPH JACOBS 1892