When I was studying in the past, I would easily fall into a misunderstanding. That is, when it comes to review, I will start from the first page of the book, read and understand everything in detail, and I can read the two-page table of contents for thirty or forty minutes. This state won't last long, and I will feel overwhelmed. However, the progress bar is slow and my patience is completely exhausted. When it came time to take the exam, I didn’t even go through the book completely, so my grades were naturally lousy. After experiencing this kind of thing a lot, I began to realize that a person's time and energy are very limited, and it is almost impossible to truly "do everything well". Many times I am particularly obsessed with the "completeness" of things. I must start reading a book from the first page and not miss a word. Learning must start from the hour, otherwise it will feel like it is missing something. In fact, this is entirely caused by the excessive pursuit of perfection. This is not only inefficient, but also consumes our patience in doing things. The core of the 80/20 rule lies in the reasonable allocation of time and energy. If you want to cover everything, it is better to make key breakthroughs. Spend 80% of the resources on 20% of the aspects that can produce key benefits, and these 20% of aspects can drive the development of the remaining 80%. In fact, many things in life are not as difficult as we imagine. A very important thinking mode in time management is to focus on using 20% ??of content to obtain 80% of value.