"A constant smirk upon the face, and a whiffling activity of the body, are strong indications of futility," the Earl of Chesterfield once wrote in a letter to his son.German-born psychiatrist Fritz Perls considered the most difficult patients to be the clever know-it-alls, recognisable by what he called “a specific kind of smile, a kind of smirk, a smirk that says, 'Oh, you're an idiot!