两千多年前，中国东南方有两个小国，一个叫吴，一个叫越。它们是邻居，也是敌人，常常打仗。
More than two thousand years ago, there were two small states in southeast China: Wu and Yue. They were neighbors and enemies, and they often fought.
有一年，吴国打败了越国。越王勾践没有办法，只能向吴王夫差投降。
One year, Wu defeated Yue. Goujian, the King of Yue, had no choice but to surrender to Fuchai, the King of Wu.
夫差把勾践带到吴国，让他做仆人的工作：养马、扫地、伺候自己。勾践都照做了。
Fuchai took Goujian back to Wu and made him do a servant’s work: caring for horses, sweeping, and serving the king. Goujian did all of it.
勾践装得很听话、很忠诚。三年以后，夫差真的相信了他，就让他回国了。
Goujian pretended to be obedient and loyal. After three years, Fuchai actually believed him and let him return home.
勾践没有忘记受过的苦。他睡在柴草上，还在座位旁边挂了一颗苦胆。苦胆的味道非常苦。
Goujian never forgot the suffering he had endured. He slept on a pile of firewood, and he hung a gall bladder beside his seat. Gall tastes extremely bitter.
每次吃饭前和休息前，他都要尝一尝苦胆，然后问自己：“你忘了在吴国受的耻辱吗？”
Before every meal and before every rest, he would taste the bitter gall and ask himself: “Have you forgotten the shame you suffered in Wu?”
勾践和老百姓一起种田，也鼓励大家养蚕、生孩子。国家越来越富，人也越来越多。
Goujian worked in the fields alongside his people, and encouraged them to raise silkworms and have children. The country grew richer, and its people grew more numerous.
这时候的夫差很骄傲。他去北方打仗，想当各国的领袖，吴国却越来越空虚。
By this time Fuchai had become proud. He went north to fight wars and wanted to be the leader of all the states, while Wu itself grew weaker and weaker.
多年以后，勾践带兵攻打吴国。他一次一次地打，终于把吴国灭了。夫差非常后悔，自杀了。
Many years later, Goujian led his army to attack Wu. He fought again and again, and finally destroyed the state of Wu. Fuchai was filled with regret, and killed himself.
后来，人们用“卧薪尝胆”这个成语，形容一个人忍住屈辱、刻苦努力，一定要实现自己的目标。
Later, people used the idiom 卧薪尝胆 — “sleeping on firewood and tasting gall” — to describe someone who endures humiliation and works bitterly hard, determined to reach their goal.