Richard Feynman had the uncanny talent for making things so simple, that anyone could understand it. He could look at anything and figure out what is critical to understand it, and remove everything else out of the equation. This comes out somewhat from being trained in science, but he had that special gift, which was beyond all of this.
I have often felt very inferior and stupid whenever I have heard him talk, or read his writings. And I mean this in a good way. He was a magician, and if you looked at him talk, or try to get an insight into his way of thought, you would soon realize that he thought about things in a way that no one else every thought about them. I forget who said this, but someone once said that if you ask Feynman how an electron would behave in a certain situation, he would ask himself: “If I were an electron, what would I do in this situation?”
All scientist in specific and thinkers in general, have a framework for their thought process. You generally, have a framework, upon which you work. You build upon what you know, and use your existing knowledge to understand something new.
In many fields, not only science, the framework itself is so large, that understanding only the basics itself is a lot of work. Take an Accountant for example; He or she will have to know the 3 basic rules of Accountancy. On top of that you need to know your local laws. Add to it the conventions followed in your industry and so forth. Very soon, the knowledge base evolves to a humongous size. No wonder, filing your tax returns is such an annoying task. I should know; I did that just yesterday.
Something similar happens when one is describing basic physics to a lay person. I have no problem understanding how EM fields propagate, and how light is given out by an electron, when it comes down to ground state from and excited state. I have no problem accepting the fact that light is neither a wave nor a particle, but can behave like a wave under certain circumstance and like a stream of particle under some other circumstances. I can sleep perfectly at peace, knowing that particles themselves behave wave-like in some circumstances.
But when you try to explain these kinds of things to the lay person, it is often very difficult to convey the exact meaning without taking too much out of it. We tend to take these things very trivially, because they have become a part of our framework of thinking.
Here is a video of the great master himself explaining this, and telling us why he prefers not to cheat, by dumbing down the explanation.