She doesn't understand emotion, she doesn't understand love, she only understands hate.
Hatred was taught to her by her mother, who always said to her:
Yue'er, in this world, only the word "love" hurts the most.
But before she died, her mother told her not to hate...
Mother, how can I not hate now that I have learned to hate?
I promise no more hatred, what else do I have left in this world...