人不够优秀，还能有变得更优秀的空间，可是没有自知之明，就没有变得更优秀的动力和恒心，也就一文不值。
Mediocrity means there’s still room for improvement. However, the motivation and the perseverance to improve will evaporate with the absence of proper self-knowledge. That’s how one becomes a worthless parasite who deserves only despise.
