战国时代，楚国有一个叫庄辛的大臣。
他发现楚襄王总是在享乐中度过时间，不再关心国家的事情，这让他很担忧。
一天，他对楚襄王说：“大王，您经常和州侯、夏侯、鄢陵君、寿陵君一起玩。他们都是贪图享乐的人。如果大王再不管理好国家，楚国可能会有危险。”
然而，楚襄王没有听从庄辛的建议，反而生气地说：“现在天下太平，怎么可能有亡国之祸呢？”
庄辛冷静地回答：“如果您继续和他们在一起，楚国一定会灭亡。如果您不相信我，就请允许我去赵国避一避，看看会发生什么。”
庄辛在赵国待了五个月后，秦国真的攻击了楚国，并占领了都城和其他地方。
楚襄王逃到了城阳，想起了庄辛曾经对他说的话，感到非常后悔，于是派人去找庄辛。
庄辛回来后，楚襄王对他说道：“我当初没有听你的劝告，才会有今天的局面，我现在该怎么办呢？”
庄辛回答说：“有句老话说：‘看到兔子再让猎犬去追还不算晚；羊跑了再去修补羊圈也不迟。’”
这次，楚襄王完全接受了庄辛的建议，并封他为阳陵君。
在庄辛的帮助下，楚襄王重建国家实力，最终收复失地，度过了危机。
后来，“亡羊补牢”这个成语被用来比喻犯错后只要有心振作，及时改正，一切都还来得及。
In the Warring States period, there was a minister named Zhuang Xin in the State of Chu.
He noticed that King Xiang of Chu spent most of his time enjoying himself and no longer cared about state affairs, which made him worried.
One day, he said to King Xiang of Chu, "Your Majesty, you often play with Duke Zhou, Xiahou, Yanlingjun, and Shoulingjun. They are all pleasure-seekers. If Your Majesty does not manage the country well, Chu may be in danger."
However, King Xiang of Chu did not listen to Zhuang Xin's advice. Instead, he became angry and said, "Now the world is at peace. How could there be any danger of losing the country?"
Zhuang Xin calmly replied, "If you continue to stay with them, Chu will surely perish. If you do not believe me, please allow me to go to the State of Zhao to avoid danger and see what happens."
After staying in the State of Zhao for five months, Qin really attacked Chu and occupied the capital and other places.
King Xiang of Chu fled to Chengyang and remembered what Zhuang Xin had said to him. He felt very regretful and sent someone to look for Zhuang Xin.
When Zhuang Xin returned, King Xiang of Chu said to him, "I did not listen to your advice before, which led to today's situation. What should I do now?"
Zhuang Xin replied, "There is an old saying: 'It is not too late to send the hound after seeing the hare; it is not too late to mend the fold after losing sheep.'"
This time, King Xiang of Chu completely accepted Zhuang Xin's advice and appointed him as Yanglingjun.
With Zhuang Xin's help, King Xiang of Chu rebuilt the national strength and eventually regained the lost territories, overcoming the crisis.
Later, the idiom 'mending the fold after losing sheep' was used to比喻 making corrections in time after making mistakes is still worthwhile.
