Darcy has a 'right to be proud,' as Charlotte labeled him: well, Elizabeth has a right to think him vain, too. He has at least one sycophant hanging around, giving him over-the-top praise constantly: how was Elizabeth not to know that he did not enjoy it as much as Lady CatdB liked her flatterers? And another friend who thinks the world of his experience, opinion, and understanding; unconscious, unplanned, hourly flattery coing from someone by means deficient himself. Elizabeth thought Darcy expected a 'yes' to his proposal, despite no obvious courtship, and no attempt on his side to soften his insulting references to the obstacles to a match. He became angry when refused - not dejected, not embarrassed. Like Mr. Collins, he was MAD.