Yi Qiu was known as the most famous expert at chess throughout the land. Once he gave lessons on chess to two men. One of them was completely absorbed in his teaching, listening attentively to Yi Qiu while the other, who seemed to be listening, had his mind on something else. In fact, he was having a fancy that a swan was flying towards him and he had in his hands a bow and an arrow, ready to shoot. As a result, though he was having the same lesson together with the first man, yet he turned out a much inferior pupil.
If one does not give single-hearted devotion to it, no skills will be learned.