The defense minister of the state of Chu noticed that one of his subordinates（下级）, an eighty-year old blacksmith, and still maintained masterly craft despite of his old age.

He inquired of the old man about the reason. The old man replied, "It is because I abide by the rules. I have liked forging waistband hooks ever since I was twenty. I have been concerned about nothing but waistband hooks, and never looked carefully at things other than hooks. By doing so, I have had a lot of time and energy to master what I wanted to master. Once I reach this realm, all things come into my usage."

楚国的大司马见属下的铁匠虽然年已八十，但记忆仍然精湛，便询问其中的原因。

老人回答说：“我遵守行为的法则呀。我二十多岁的时候，就喜欢锻打腰带钩，对于别的什么，都不关心；不是腰带钩，我从不仔细去看。这样，我就有了足够多的时间和精力，去熟练掌握想要掌握的东西。一旦达到这种境界，万物都会为我所用！”