In ancient Greece, those who sought counsel from the Oracle at Delphi passed under an arch that bore the inscription, “Know thyself.” Presumably, those who did not know themselves would be ill-equipped to hear the truth. Yet unanswered questions reverberate down through the ages: what form does such self-knowledge take, how are we to gain it, and what difference will it make if we do? Knowing yourself could mean many things. Knowing your strengt…