We must first understand what "society" is. Society generally refers to people who live together in a certain environment. Strictly speaking, high school, junior high school and primary school can also be regarded as a "small society". But college is different. We are freer, have more choices, know more people and have more time and space to ourselves.
In college, we can see many people's different choices in advance, which is a small microcosm of the real society. There are students who go to practice very early, and they are exposed to projects and practices; Some brothers are willing to study and study in depth the academic issues they are interested in; There are also younger brothers who are content with the status quo and enjoy the good times and wanton youth during their college years.
I think one of the important reasons why universities can be called "small society" is openness.
Unlike high school and junior high school, universities are full of courses every day. Universities have the right to choose their own topics. They can skip classes, join many interesting clubs and do all kinds of interesting activities.
In college, although everyone's experience is different, everyone has made their own choices in college. From the moment I entered school, I decided to choose my major, courses and clubs. Everyone's trajectory is different. Because of the university, we can face the truth of this world earlier.