I've been working as a Java developer for almost a year now, after getting a job without fully understanding the national subsidized classes I took. I just had questions about why we use things and what the principles are. But after watching this lecture, many of my questions were answered and there were so many "aha!" moments! Thank you for the great materials and easy-to-understand explanations. I've already paid for the advanced course! I'm going to diligently follow the roadmap~~