I thought the man who treated all problems as nails, because he only had a hammer in his hand and no other tools to solve problems. At the same time, he only looked at the problem from one angle, which only showed that his realm was not high, and his knowledge could only be understood in this way. He could not change his perspective and could only see the small interests in front of him! For example, if we study just for the sake of learning, it is a very helpless thing, even a very painful thing. If we regard learning as acquiring knowledge and laying a foundation for future life development, it may be another situation.