There was a person named Yi Qiu, who played the game of I-go best in his country, in the Spring and Autumn Period (770 BC-476 BC).
Two persons learned the game from Yi Qiu. One was very attentive, caught every word his teacher told him, and spent all of his energy on learning the game. Another person thought the game of I-go was not very difficult to learn, and so he was not very serious, though he also followed Yi Qiu for the skill. When holding chessmen in his hand,he was thinking about the birds flying in the sky and how to shoot them down.
Though they learned from the same teacher, the second person was never the match for the first person. Is this because of his intelligence?
Certainly not. Playing the game of I-go was just a small skill, but one couldn’t become an expert in the skill if he failed to focus any of his energy on learning. The person was diverted from his learning, so he certainly lost to another person.
This proverb comes from Mencius: Gaozi Part One, and means a whole heart and concentration of energies.