Although Mr. Xue's status is low, the standard for the world to choose Mr. Xue is very strict. Besides good conduct and profound knowledge, he also needs a teacher with rich teaching experience. "You must choose a person who has a good personality, thorough knowledge, is not addicted to smoking or gambling, but does not stop, is not afraid of trouble, and is diligent in explaining, which is enough for this position." Kong Yiji, like Lu Xun, was not invited to be Mr. Xue, not only because he "doesn't even have half a scholar" (because most of Mr. Xue was born as a boy), but also because of his bad habits such as idleness and laziness, and of course, his sour pedantry.

For a considerable number of teachers in private schools, it is not easy to teach students well and gain a good teaching reputation. Zhu Zaiyu, a writer in the Ming Dynasty, wrote a poem "Awakening the World", in which he wrote: "It is difficult to teach, and it is easy to make virtue hate. People are in charge of access, and those who are hungry and cold are poor. I hit him and said I wouldn't watch it. If you don't hit him, you will say that the teacher is not strict. " The word "big" in the poem reflects the extremely common ways and attitudes of teachers in ancient private schools, which is certainly unscientific now. However, in ancient private school education, "beating" is an important embodiment of private school rules and strict teaching of teachers. There are two reasons for this strictness. One is the teaching order requirement of teachers' dignity respected by traditional Confucian ethics, and the other is that parents who hate iron and cannot produce hope that teachers will be stricter. Therefore, pointer and ruler have become the most effective tools to maintain teaching order and scare naughty children in private schools, and also a powerful means to safeguard teachers' dignity. The so-called "a heartless bamboo, if you don't beat it or read it, you don't have to send it to read it if your parents love you" is not only the teacher's concept of corporal punishment, but also recognized by parents or society. As long as they don't "beat" too much, there are not a few parents who "say that teachers are not strict". On the contrary, more parents want Mr. Xue to be strict, which is consistent with the mentality that many parents want their children to succeed.