Xi Shi's beauty was said to be so extreme that while leaning over a balcony to look at the fish in the pond, the fish would be so dazzled that they forgot to swim and gradually sunk away from the surface, birds would forget to fly and fall from the sky, the moon would fade, and flowers would close their petals in shame in comparison to her. (Thus the idiom 沉魚落雁, 閉月羞花 which is used to compliment someone's beauty.) [source: Wikipedia]