There is a humorous and thought-provoking scene in Bollywood. The mechanical teacher asked Rancher what machinery was in class. Rancher explained what machinery is in very simple language (machinery is something that can save people's labor), and illustrated it with zippers on pants and electric fans on the ceiling. The story made the whole class burst into laughter, and the teacher was furious, forcing Rancher to answer in very professional terms. Rancher admitted that he didn't know, so the teacher kicked him out of the classroom. The rancher came back, and the teacher asked him why he came back. Rancher used many modifiers to indicate that he had forgotten something. The teacher was at a loss, and finally asked what Rancher was saying, which made the whole class burst into laughter. Rancher refuted the teacher's concept of describing concepts in professional and complicated language with personal practice. Very humorous and clever expression of the view that the mastery of knowledge lies in understanding and application, not in rote memorization and becoming a nerd.

This movie inspired me a lot: simplify complicated things. In daily life and study, people have to face many complicated and thorny problems, and the seemingly chaotic situation suddenly confuses most people. For a very simple example, any concept in a textbook needs to be described in long and precise language. In fact, there are two main functions: