In passive learning, others decide what to learn. For example, in junior high school, teachers decide what to learn. Those written in textbooks are considered correct, and those not written are considered incorrect. You can not choose textbooks. You only receive the given textbook.
On the other hand, in active learning, you decide what to learn. You choose textbooks by yourself. Depending on what you want to learn, textbooks may not exist.
The ratio of passive learning and active learning reverses in university. At university, you need attitude to learn by yourself rather than be taught by your teacher. For example, in the form of elective courses, you have to make decisions about what you learn. To buy reference books or not is sometimes depends on your judgment.
In graduation research, you have to decide themes yourself, to learn by yourself, to think and to create new knowledge. However, it seems that some people do not realize this change in learning style and graduate from university without learning actively.
In junior high school exams, you have to give the same answer as the correct answer. However, in the research at the university, you have to answer the problem that nobody has yet found the correct answer.
The problem of the exam of junior high school is made to be solved. If you correctly execute the method you taught by the teacher, you get the correct answer.
However, there is no sure way to get answers for unsolved problems at universities and the real world. If there is a way to solve the problem surely, someone solves the problem, and the problem is not left as unsolved problem. (*1)
Your supervisor may advise on research method, but it is not a method to surely solve the problem, but a method likely to solve the problem. There is no guarantee even if you act as you have learned that you achieve valuable results. It is necessary to actively learn and think by yourself.
If you can only learn passively, people around you think that you can only move as they told you. And they give you a type of job that repeats a routine way. It is because, to change your way of thinking is difficult, especially you can not learn by yourself.
*1 Or nobody except you thinks that the problem is worth to solve.