There was an excellent archer named Chen Yaozi in the Northern Song Dynasty (960-1127).
One day, he practiced archery at home, and hit the target with eight or nine out of ten arrows. The viewers applauded and exclaimed, “Great archery!” Chen Yaozi also felt very pleased. However, an old pitchman selling edible oil nearby just nodded slightly, and didn’t think high of Chen’s archery.
Chen Yaozi was very unhappy, asking “Are you also an archer? How do you like my archery?” The pitchman answered candidly, “I don’t know archery. You do it ok. However, archery doesn’t have any secret. Practice makes perfect.” Chen Yaozi became very angry, “What’s your skill? How dare you so comment on my archery?”
The old pitchman then took out a copper coin, and covered it on the orifice of a gourd used to contain edibal oil. Then, he fetched a spoon of oil, held the spoon high, and emptied the oil into the guard through the hole in the coin. There was not even a drop of oil beyond the coin hole after the pitchman emptied all the oil. The old man said to Chen Yaozi, “I also have no secret to empty oil, just because I am skillful.”
After seeing the pitchman empty oil, Chen Yaozi felt very ashamed. From then on, he never felt complacent again, and practiced the archery with modesty.
This story comes from Recordof CountryLife written by Ouyang Xiu. People have derived the proverb. The proverb means no matter what you do, you will find out many knacks as long as you practice hard and master the rule.