Teaching people about the hazards of multitasking doesn’t lead to less texting in the car; learning about the weakness of the will doesn’t increase the success of diets; knowing that most people are overconfident about the future doesn’t make us more realistic. The problem isn’t that we’re stupid—it’s that we’re so damn stubborn. … [Kahneman's] greatest legacy, perhaps, is also his bleakest: By categorizing our cognitive flaws, documenting not just our errors but also their embarrassing predictability, he has revealed the hollowness of a very ancient aspiration. Knowing thyself is not enough. Not even close.