I think the main reason is that our main job before college was to study, but when we went to college, it was different. We pay attention not only to study, but also to many things that make us unhappy or depressed. Our primary school, junior high school and senior high school all go to school near home, because naturally they all live in the same place, or they will be closer in all aspects, and there won't be much difference. But there are people from all corners of the country in the university, so it is difficult for everyone to get along with people with different personalities or customs.

Before college, what we must have heard the most is that you should study hard and don't think about anything else. Our main task at ordinary times is to study or play with classmates, without too many other interests or conflicts. Moreover, at that time, we were more simple and naive, and we didn't think too much about anything but happiness.

Universities are different. The competitiveness of universities has begun, and students have not concentrated on their studies. There are also club competitions or class events, so there is a gap between students, because everyone wants to have more interests in matters related to interests. In college, it is equivalent to a small society, which makes you feel this kind of pressure. There is a saying that high school is busy in an orderly way, and universities are busy for no reason. This also shows the confusion in the university. We don't have a clear goal, we just want to fight for something good for ourselves, so it will be tiring if things are too messy.

We have more free time in college, but these free time make us more confused and don't want to waste time, so although we have more free time, we feel more tired rather than relaxed. Without intimate friends, without a goal, we have to deal with all kinds of uninterested things and interpersonal communication between classmates, so we are more and more tired and depressed in this life.