春秋的时候，有一个国家叫吴国，国王叫做夫差。
他决定去攻打另一个国家——齐国。
这时候，还有一个国家的国王勾践，他带着他的部下来见夫差，并且送了很多礼物给夫差和他的大臣们。
大臣们都觉得很开心，但是有一个人却觉得不对劲。
这个人就是伍子胥。
他心里想：“这是勾践在收买我们吴国的人，让我们的国家变得松懈，不再警戒，然后好把我们消灭掉！”
于是他就去找夫差，告诉他：“勾践才是我们真正的心腹大患！他表面上看起来是服从我们，但其实是在计划着怎么吞并我们。如果你不早点把他灭了，以后就会有大麻烦。你去打齐国是没有意义的，那个地方就像一块没有用的石头田地一样，这样做太傻了！”
可是夫差并不听伍子胥的话，还让他自杀。
结果，后来吴国真的被勾践给消灭了。
“心腹之患”这个成语就用来形容那些藏在内部的祸害。
如果不小心处理，这些祸害就会像疾病一样，严重到足以威胁到我们的生命和生存。
During the Spring and Autumn period, there was a country called Wu, ruled by a king named Fu Chai.
He decided to attack another country - Qi.
At this time, there was also a king from another country named Gou Jian, who came with his men to see Fu Chai and presented many gifts to him and his ministers.
The ministers were all very happy, but one person felt that something was not right.
This person was Wu Zixu.
He thought to himself: "Gou Jian is buying off our people in Wu, making our country lax and no longer vigilant, so that he can destroy us!"
So he went to find Fu Chai and told him: "Gou Jian is our real heart's worry! He looks like he is obeying us on the surface, but in fact, he is planning how to annex us. If you don't get rid of him early, there will be big trouble later. It's meaningless for you to attack Qi. That place is like a piece of useless stone field. It's too foolish to do that!"
But Fu Chai did not listen to Wu Zixu's words and even made him commit suicide.
As a result, Wu was later destroyed by Gou Jian.
The idiom 'Heart's Worry' is used to describe those hidden dangers within.
If not handled carefully, these dangers can become like diseases, serious enough to threaten our lives and existence.
