Haha, I'm genuinely intrigued to see the contents of that book. It could certainly be copy/paste from the Mozilla docs, but who knows! I was pleasantly surprised by this video about the JS event loop, although in fairness it is a lecture at a conference rather than a made for youtube video. Regardless, the length of the video made me question how necessary it was but I ended up watching the whole thing and enjoyed it. https://www.youtube.com/watch?v=8aGhZQkoFbQ