I don't understand why the ratings are so good.. 1. It feels like a professor is teaching a college class, making mistakes and thinking about things on his own. From the perspective of a student who is listening, you often find yourself following along and thinking, "Huh? This is weird???? This should be done this way?" and then fix it first, and then you find yourself looking for it in the video. 2. Fixing parentheses takes up a lot of time. He often copies and pastes code, but he doesn't erase parentheses properly and just puts them in, so he uploads everything he did to fix the parentheses in the video. 3. It seems like a lecture for complete beginners, but he doesn't explain why he does things this way. He just says, "Do it this way~" and moves on. There is no explanation of why this callback function is included here, how the parameters are passed, etc. Of course, it's hard to explain because it's implemented by bringing in multiple APIs and inserting them, but in most cases, there's no explanation at all... 4. I really don't want to point this out, but it's so annoying that I'm mentioning it.. You kept being dull, so I looked and saw that you were talking about done.. I wondered what you were talking about, so later I saw a few more things that made me think, "Oh, so that's how you pronounce it." 5. Since it's a lecture that's been uploaded for a while, there are parts where arrow functions aren't used or var is used instead of let, so please refer to it when watching the video. Light? It seems like a good lecture to listen to, but if you just fixed the parentheses that were missed while copying and pasting, or the typos, and the errors that occurred when copying and pasting without editing, you could have reduced the 4 hour and 30 minute lecture to 3 hour and 30 ~ 4 hours.. It doesn't require technology to remove the video.. If you just removed this, it would have been a video worth at least 4 points.