Elon Musk says when hiring, evidence of exceptional ability matters more than any other credential. "Did they face really difficult problems and overcome them? You wanna make sure that if there was some significant accomplishment, were they really responsible, or was somebody else more responsible?" "Usually the person who's had to struggle with the problem, they really understand it. And they don't forget, if it was very difficult." "There's no need even to have a college degree. At all. Or…