// Albert Einstein said: "If you can't explain it to a six year old, you don't understand it yourself." I like to think this is true about explaining things to my parents
I think that is probably a "folk quote", the attribution to Feynman is also inaccurate AFAIK. He said something similar though:
> 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.”
– Feynman’s Lost Lecture by David and Judith Goodstein
Neither Einstein nor Feynman. It's just one of those quote memes that get stuck to famous people because those are the most likely attributions to get repeated.
I found it ironic that this initial quote seemed to be the intent of the article... which then goes on to display charts and equations that are unlikely to jive with a six year old.
This concept is not about explaining things in terms a 6 year old can understand.
It's about understanding the subject matter well enough that if necessary you could simplify and elaborate on topics to bring your audience to your level of understanding.
(i.e. - understanding your subject vs. being able to recite facts)
You really come to terms with how well you know a subject when you sit down and try to teach it to someone else.
> 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.”
– Feynman’s Lost Lecture by David and Judith Goodstein