Actually, I don't usually write course reviews, but I think this course is really good. It explains in detail the core things you need to know in JS, such as execution context, this binding, prototype, closure, etc., so even if you don't understand it well at first, you will definitely understand it if you keep listening. In the intro, you mentioned that it would take 6 months to understand prototype, but I felt sorry because the explanation was so detailed that I felt like I was eating it in a day.