An example of "cautious independence"?

Xu Pu, a teenager, was calm and mature. When he was studying in a private school, he was never unsmiling. Once the teacher found that he often took a small notebook out of his pocket and thought it was a child's plaything. When I took a closer look, I found that I wrote my own Confucian classic quotations, which was greatly appreciated.

Xu Pu also followed the example of the ancients, and constantly checked his words and deeds. He put two bottles on his desk to store black beans and soybeans respectively. Every time I think of a good idea, or I say a good word and do a good thing, I throw a soybean into the bottle. On the contrary, words and deeds are wrong, throw a black bean.

At the beginning, there were more black beans and fewer soybeans, so he constantly reflected deeply and constantly encouraged himself. Gradually, the number of soybeans and black beans leveled off, so he made persistent efforts to be more strict with himself. Over time, the soybeans in the bottle accumulated more and more, compared with which, black beans gradually became insignificant.

He kept this habit until he became an official. Under this lasting restraint and encouragement, he constantly cultivated his morality and improved his moral character, and finally became a respected generation of famous ministers.