Richard Feynman Explains How Magnets Work
Adam Rifkin stashed this in Science!
Top Reddit comment:
It gives you a new appreciation for anyone trying to teach. Where do you begin the shared baseline of understanding you try to build upon? What will you sacrifice if you trade actual understanding for a workable analogy that's quick but intellectually dishonest.
It also points out the problem with arguments and debate. Many people refuse to accept anything the other person says and so they can never reach a shared baseline of understanding to begin and build upon, until they reach a view point where the full proof trail can be traced back down to that foundation.