There are three musts that hold us back: "I must do well. You must treat me well. And the world must be easy." And I sometimes think that as long as we keep the second must, which is socially learned, then some screwballs 100 years from now will manufacture atomic bombs in their bathtub and maybe annihilate the whole human race because they demand that the rest of the world must agree with their dogmas. When we don't agree, they may zap us.