In some ways, I feel like I'm regressing because I've been using it the way I always used it, even though I need to know the characteristics of Java properly while working, so I came across Ki-seon's lecture while trying to study it again. I'm watching it along with design patterns and refactoring. There are many parts of Ki-seon's lecture that are related to the areas used in practice, and since he also provides necessary background information, I think it's very helpful for expanding my knowledge. And the best part is that it's not a set framework, but the process of solving problems that arise in real life is also a good experience. I tried Effective Java once before with a book, but I just progressed through it and couldn't properly digest it. When I read it in a book, there were a lot of things that were stiff and incomprehensible, but I think Ki-seon is filling in the gaps of knowledge that I couldn't access in the book. Is it just a feeling that the organization is getting better compared to the old YouTube videos? In the past, it was live coding, but it was difficult to concentrate, but these days, it seems that organizing knowledge by giving questions to think about while organizing in between is also helpful. It is difficult content, but if you follow it step by step, it will be very helpful. I am looking forward to the remaining 4 parts :)