Agree. Good work. Let me add one more thing. A Usually Persistent Truth: the farther you are from when you learned something, the worse you are at teaching it.

Agree. Good work. Let me add one more thing. A Usually Persistent Truth: the farther you are from when you learned something, the worse you are at teaching it. Khan's ability to learn something and turn around and teach it is likely the reason it's accessible and enjoyable for students.