For students who are not majoring in theoretical physics, it is important to remember that exercises will not be too difficult without real understanding. So on the whole, it's not difficult. As long as you study hard, you should be able to pass the exam.

For students who study theoretical physics, the requirements will be higher, but some people still adopt the above methods and barely pass, although they don't really understand.

If you want to understand quantum mechanics, it's really difficult, and it's not just time and effort. Let me give you an example to illustrate: we read that experts tell apples and their flavors, memorize them, answer questions or tell them to others, just like experts, but we and those who really know pears and apples will understand that this is just a verbal expression. If you carefully taste a few apples and pears and then talk about your experience, you and the wise will know that you really know the taste of these two fruits, but those who haven't tasted them can't tell the difference between you and the truth.

To recognize quantum theory, it is necessary to pass a difficult psychological barrier, that is, to admit that the framework of classical physics, which was almost perfect, is imperfect, which is quite painful for a physics student who has come step by step, and must be psychologically prepared to be thoroughly remoulded.