I will leave an honest review. I personally looked around several spring lectures, and I also took Kim Young-han's introductory lecture. To be honest, I had a hard time listening to the instructor's introductory lecture. That's because I didn't really get anything out of it. I just followed along, but I was frustrated because he didn't give me a clear explanation of why it was like that. Still, after reading many reviews, I ended up paying for Kim Young-han's lecture and learning, and I realized that everything was in the instructor's plan. The instructor recommended the wild study method, and this study method is a study method that follows along first, even if it's frustrating, and then delves into it later. In the Spring Core Principles Basics that I listened to, I felt like I had a drink because I felt like I had learned something from the introductory lecture and realized, "Ah! This is it!" I plan to take JPA for the next lecture, so I'm looking forward to it. Thank you for providing such a great lecture.