When I first encountered Spring, I felt like I had hit a wall and was so lost, but I saw an article by Kim Young-han that said Spring is unconditionally good, and I took the lecture. While I was taking the lecture, the lecturer explained the core principles of Java, 'Why shouldn't I do this, why should I write it this way?' The core principles were explained so easily that I could understand concepts that I couldn't understand even after thinking about them for hours on my own, and I felt catharsis after only 3 hours of lecture. It's the first time I feel regretful that I couldn't attend the lecture when I should be sleeping. I'll finish it quickly and take other lectures!