In chapter 9 Lizzy says to Mr. Bingley, "Oh! yes - I understand you perfectly." She genuinely seems to believe she is good at interpreting peoples behaviors and characters.
Yet in chapter 10 she misinterprets Darcy's behavior. "She could only imagine however at last, that she drew his notice because there was something about her more wrong and reprehensible, according to his ideas of right, than in any other person present."
Are there other examples of Elizabeth not living up to her belief in her own abilities?