I believe there are many differences between the worlds of high school and college. First of all, there are much more responsibilites in college. You are living on your own and need to learn to rely on yourself and not others like parents as some may have before college. Also, things like the environment around you. To explain, students are coming from schools that range from a class of 30-500 kids and in college there is like 5,000 per a class or more.
Classes work differently.
In that I mean there are no bells, and if a teacher gets done with what they wanted to go over, then the class is over regardless of time. In addition, some teachers ask to be called by there first name which is something that never happened in high school. When a student as reached there senior year in high school they pretty much know almost everyone in there class. However in college when you are a senior you probably won't know half of your class because of how many there are.