It is a useful lecture because it explains Java grammar and other things in detail, along with design patterns. The disappointing thing is that it only explains each pattern sequentially and does not explain similar patterns in an integrated manner. I wanted to hear about how you struggled between theory (design patterns) and practicality (work schedule, no money, etc.) in practice and how you overcame them, but I am disappointed that there is nothing like that. When I only think about the explanation of design patterns, I can't find any particularly good points compared to other design patterns on YouTube, etc.