This math teacher is going to make you miss math class. No, he really is. Or at least he'll make you wish that you had him for math. To explain imaginary numbers to his class, he put together an excellent and surprising video of himself teaching. I have done a lot of teaching (and still do, time to time), and I can tell you that great preparation makes a huge difference, but I don't think I ever put so much work into one lesson as this guy.
There isn't really an actual math lesson in the video, but there's the start of one, and you can bet the students are happy to be there.