You cannot teach anyone something unless you can put it in their terms, not yours.
In the early 1960s, Richard Feynman gave a series of undergraduate lectures that were collected into a book called the Feynman Lectures on Physics. Absent from the book was a lecture Feynman gave on planetary motion, but a later finding of the notes enabled David Goodstein, a colleague of Feynman’s, to write a book about it: Feynman’s Lost Lecture. From an excerpt of the book published in a 1996 issue of Caltech’s Engineering & Science magazine:
Feynman was a truly great teacher. He prided himself on being able to devise ways to explain even the most profound ideas to beginning students. Once, I said to him, “Dick, explain to me, so that I can understand it, why spin one-half particles obey Fermi-Dirac statistics.” Sizing up his audience perfectly, Feynman said, “I’ll prepare a freshman lecture on it.” But he came back a few days later to say, “I couldn’t do it. I couldn’t reduce it to the freshman level. That means we don’t really understand it.”
John Gruber writes the simple explanations are the goal at Apple as well:
Engineers are expected to be able to explain a complex technology or product in simple, easily-understood terms not because the executive needs it explained simply to understand it, but as proof that the engineer understands it completely.
This is what great teachers do – make the complex simple. And if they do not understand it enough, they cannot do this.
I learned this first hand when, as a first year graduate student, I have to act as a teacher for undergraduates in their Biochemistry class. I remember having a hard time explaining the biological definitions of acid-base. I could not answer some of their questions until I had answered all them myself.
Until I had a clear insight into why I was confused and how to overcome that confusion.
So, in trying to figure out how to discuss this will students, I had to figure out how to really explain it to myself.
Of course, just simplifying things does not make one a great teacher. In fact, most false theories that drive denialists come from offering a false but simple explanation.
It can be relatively easy to tell the difference.
A teacher like Feynman was able to convey truth that lead to greater explorations of more complex subjects. Those that feed denialists convey lies that serves to hinder further exploration.
One knows that there is much more to know and seeks further knowledge. The other is afraid to know more and seeks to stop.