Now that I've taken Java Intermediate 2 and want to learn Spring, I tried 'headbanging'. As expected, it reminds me of something huge like an 'elephant' or 'the vast ocean'. Just like you said, Practical Java Intermediate 2 felt like the minimum requirements. Really.. I'll review the introductory lectures more, and I think I'll understand it before I know it if I move on to the basics. It was the same with Java, lol. Even with the minimum requirements, the game won't run without a little lag, so I'll trust the instructor and try Spring too!!