Mencius once remarked that the great affliction of people is their fondness for teaching others. The line comes from the 'Li Lou I' chapter of Mencius, and it is easy to misread. Mencius was not disparaging the teaching profession. Here 'teach' is a verb: the act of instructing, not the job of being a teacher. Mencius, honored as the 'Second Sage' after Confucius, has shaped Chinese culture for centuries, so the observation has lasted for a reason.
The Tang writer Liu Zongyuan later noted the same tendency in his own time. After the Wei and Jin periods, he wrote, people became increasingly unwilling to honor teachers; by his day, anyone who presumed to teach was likely to be laughed at as a crank.
Modern life has made people more independent and more self-contained, and the reluctance has only grown. Those who consider themselves clever are especially unwilling to play the teacher. Many suspect that teaching is really a way of proving oneself, of feeding vanity. So in ordinary conversation people keep their experience and opinions to themselves and offer polished, harmless remarks instead.
A trainee barber gives you a haircut that looks as if it was chewed by a dog. Your colleague will not say it is ugly. They will call it 'unusual' or say it has 'character.' You spend a small fortune on a renovation, and the result mixes Chinese and Western elements while managing to be both classical and modern. Friends will not tell you that your taste is questionable or that you wasted money. They will praise the luxury and mention that even the drying rack was imported. You fail the college entrance exam, go to a vocational school, and choose computer science because it seems like the hottest field. After graduation you discover that your competition is full of university graduates; finding any job is hard, never mind a salary of twenty or thirty thousand yuan a month. Yet when you were choosing the major, acquaintances who were not close to you would not have said that computer science at a vocational school is less promising than welding or machine tools. They would have said: wow, that is a high-end field, with high pay waiting at the end.
The urge to instruct may indeed be part of human nature. My father used to tell me how hard life was when he was a child, using those stories to teach me frugality. Now he tells the same stories to my son. Decades have passed and the circumstances are completely different, but he still enjoys passing on the lessons and habits of his youth. My son is eight and my nephew is six. My son often tells his cousin stories he has invented, or explains the game Minecraft to him, and he will not tolerate interruptions. From childhood to old age, the pattern repeats. It looks very much like a natural inclination.
But there is a difference between this and what Mencius described. When my father tells my son about his early life, or when my son tells my nephew a story, the listeners enjoy it. They do not feel that the speaker is proving himself or indulging vanity. So it is not quite 'liking to teach' in the bad sense, still less an affliction. Teaching others is not necessarily a pathological habit.
Why is the urge sometimes a sickness and sometimes not? The answer seems to lie in closeness and distance. When someone close to us teaches, it tends to be care and advice. When someone distant teaches, it can look like showing off. The same pattern extends outward: a person of high status who instructs is seen as concerned, while a person of low status who instructs is seen as overreaching. The rich who teach are transmitting wisdom; the poor who teach are presuming too much. This probably comes from our deep deference to power and wealth. But is the wisdom offered by the powerful or the rich really their area of expertise? An official lecturing you on programming is no match for a working programmer; a millionaire lecturing you on health is no match for a village doctor. Most people are close to power and wealth, but not to the Way, and so the real Way gets discarded.
The Chinese sentence can also be punctuated differently. Instead of 'the trouble with people is that they like to teach others,' read it as: the trouble with people is that they are too ready to assume that someone is playing the teacher. In this reading, 'to consider' is the key verb, and 'teacher' is a noun. The fault is not that people teach, but that we habitually interpret another person's instruction as a performance of ego.
Change the lens, and the same situation looks different. If you do not treat every act of teaching as vanity, as a way of showing off, or as an attack on your self-esteem, then teachers are everywhere. What you gain is the pleasure and satisfaction of learning and improving, rather than the resentment of feeling used or belittled. Confucius said that among three people walking, one is bound to be my teacher. Mencius, a later heir of Confucius, warned that the urge to teach is a trouble. Both are called sages, yet on this point they stand far apart.