To be constant is to be useful. To be useful is to realize one's true nature. Realization of one's true nature is happiness. When one reaches happiness, one is close to perfection.
ZhuangziOne whose inner being is fixed upon such greatness emits a Heavenly glow. Even though he has this Heavenly glow, others will see him as just a man. Someone who has reached this point will begin to be consistent.
Zhuangzi