Why do people with the same surname say that they were a family 500 years ago?

500 yuan was in the early Ming Dynasty. At the beginning of the Ming Dynasty, due to war and famine, the population in most parts of the north decreased sharply. In order to maintain the rule of the Ming Dynasty and resume production, the court decided to emigrate from Shanxi to Shandong, Hebei and Henan. At that time, the most famous tree was Sophora japonica in the north of Hongdong County, Shanxi Province, because it took about 500 years from the early Ming Dynasty to the late Qing Dynasty and the early Republic of China. By the end of the Qing Dynasty and the beginning of the Republic of China, the descendants of Sophora japonica had spread all over the country. When many people meet for the first time, they happen to be fellow villagers in Hongdong, Shanxi. If you ask "What's the name of your hometown" again, and it happens to be the same surname, the questioner will say, "Ah! This used to be a family 500 years ago. This statement is quite popular.