I was worried that I wouldn't understand it since it's been years since I learned Java, but I understand it very well. It really touches my heart with the greatness of object-oriented design and Spring, which I wouldn't have known if I had just read the book. It's so amazing and fun how everything fits together like a puzzle or Lego. The people who made this seem like gods of organization and design, and the instructor who explains this seems like a god of lectures.