You worked on something new, whether it’s a new skill or a new book that’s difficult to understand, and it was kind of struggling for every step. You didn’t know how well you did as you felt like struggling for each and every little thing (concepts, knowledge points, etc.) and after that journey was completed, whether it’s the course for the new skill or a book, you only knew you had done this or that but you didn’t have a clear picture of what you had got or how well you did because clearly you knew something of it but you didn’t know the whole thing. The point is how big that SOMETHING is.
Well, after some time, you are back to that thing again, whether on purpose or occasionally, and now you are surprised to see a quite different picture in front of you because of what you did the first time. You might still don’t understand some of the concepts or knowledge points but now you can have a comprehensive view from a higher level instead of only working on the concepts and knowledge points with all of your attentions. You can now have a better understanding of which parts you are not doing well yet so you can put a little more time and energy there.
And when it comes to the third round (if there is a third round), well, things might be different again as now you have a much better understanding from the basic level (concepts, knowpedge points, etc.) and the higher level (comprehensive view like how things can be done and improved with the concepts and knowledge you have gained).
No surprise people are always advise to read books a few more times, especially those classic ones. And it’s the same for other things, like new technology, skills, etc. I previously thought I should and could become quite good at something I liked to do as long as I completed the courses and got a understanding of all the concepts and knowledge points. The result of course failed me again and again. For something that’s worth doing and learning, there is no so called courses which can help people become experts from zero. It should be a process which might last longer than expected and it should be done and practised again and again because even though we feel we are doing quite well already, there is still a possibility that we face new challenges and we might have no idea on how to handle them with what we have already learnt. But it’s also a good opportunity for us to know our knowledge blank spots and get them fixed because after you become more and more skilled at something, blank spot might be difficult to find though whevener there is one found, it might cause bigger trouble.