People are not born to know, who can not be confused? If you are confused and don't follow the teacher, you will be confused and you will never understand.
This is a famous sentence in Han Yu's Shi Shuo.
The meaning of this sentence is: people are not born to understand reason, who can have no doubt? With doubts and not learning from teachers, those who become difficult problems will not understand in the end.
This is to encourage us to ask questions boldly when we don't understand, and we have to pretend to understand, otherwise doubts will accumulate.