To be great is to be misunderstood, and Feynman was a great man. I'm still not sure who decided to abuse some quotes and invent this "razor". I don't believe Feynman ever meant to overconstrain and corrupt information based on (likely incorrect) assumptions about his audience. There's no need to "dumb down" anything ever, not even for children. The information is either there or it isn't regardless of who can compreh…
This is so wrong that I can't imagine you actually meant it in the way that it quite obviously reads like.
When my 3-year old just saw is favorite toy fall from the sofa because he put it in an .. unstable position, then obviously it won't help if I explain the theory of relativity to him, cause ultimately it was gravity causing the mess. It won't help either to "dumb it down" by only explaining Newton's mechanics. What he actually needs to understand is that things fall down. Why exactly can be explained later. Much later. When he goes to university perhaps, if he chooses to and still wants to know.