This sentence means that people can change. If they had done bad things in the past, they might get rid of them now and start over. Then they should change their attitude and should not judge the present with previous evaluations. On the other hand, I used to be a good person, but now I may have gone bad for some reason, so I can't judge the present according to the label of being a good person before.

"Good reputation" in history

In history, Wang Mang's success can't be separated from his good reputation, and Wang Mang himself knows this well, so he has always been a corporal with noble character, the son of the people, and often gives his salary to poor families. In addition, we also make friends with intellectuals and often help those who have not been reused for the time being.

Such people naturally spread legends of various virtues in the ruling and opposition circles, and then Wang Mang became a sage Duke Zhou who could govern the world in people's hearts with his good reputation, and with the support of the people, he seized the supreme power of the Western Han Dynasty by abdicating, changed his country name to "new" and called himself the new ancestor.