History is fluid. Jia Jia, the principal's daughter in the movie "Water for the Donkey", said, "If the past is gone, it will only get worse". Indeed, whether it is national history or personal history, we study it only to understand what happened in the past.

If that thing was once right, we should learn to carry it forward. King Wuling of Zhao in the Warring States saw that Hu clothes were convenient to wear, which was conducive to riding and shooting, so he made all the people in the country wear short coats and Hu clothes, making Zhao quickly become a military power in the early Warring States. The story of "Zhao Wuling, Wang, Riding and Shooting" has also become a popular story.

If what happened is wrong, we must find out the reason and correct it. Only in this way will the future not get worse. That's why the world-famous idiom "learn from a mistake" came into being.

History is to improve the "intelligence" of human beings through its unique way, so that human beings can carry forward their experience in repeated successes, learn from repeated setbacks and grow into promoters of society.