Question

Why is Elizabeth Bennet prejudice?

Answer 1

How despicably I have acted!" she cried; "I, who have prided myself on my discernment! I, who have valued myself on my abilities! who have often disdained the generous candour of my sister, and gratified my vanity in useless or blameable mistrust! How humiliating is this discovery! Yet, how just a humiliation! Had I been in love, I could not have been more wretchedly blind! But vanity, not love, has been my folly. Pleased with the preference of one, and offended by the neglect of the other, on the very beginning of our acquaintance, I have courted prepossession and ignorance, and driven reason away, where either were concerned. Till this moment I never knew myself." 

Notice that sentence at the end, "'Till this moment I never knew myself"? That's some character growth, right there. Lizzy is admitting that she was "prejudiced"