 When we shift from high school to university that's a really different way of studies when you come to university. What has helped me is that when I study in university I go to the lecture for one hour and I then make notes in the lectures, understand as much as I can, and then I come back home, give another extra hour for that one hour lecture and understand, try to recap and see what I have really understood. If not then I have other ways of understanding through textbooks, through other sources like tutorials, tutors etc. But then it gives me an understanding of whether I have really understood the topic and then I feel that yes I am confident enough to be able to answer this particular question in the exam and it gives you a good feedback. When you study for your exams you know that you know this really well. So that's how it has helped me and I hope it has helped you.