Teachers in college classes are too traditional, and they are generally in a hurry, which leads to some students not learning and not knowing what they are learning. You can only learn by yourself through online classes and school resources. Although self-study without teacher's guidance will improve efficiency, I can concentrate. Maybe I can get twice the result with half the effort!
I usually study by myself through school resources when I have no classes. There are PPT and mind maps made by teachers, and even micro-lesson videos. I don't understand in class. Go back to the dormitory and turn on the laptop. You can easily understand knowledge and learn more efficiently.
Self-taught college exams give us a sense of self-discipline and improve our professional skills.