> True experts can understand from the layman's perspective and tailor the response to that level of understanding.
The Feynman paradox:
> if you can't explain it to a six-year-old you don't understand it yourself
but also
> If I could explain it to the average person, I wouldn't have been worth the Nobel Prize
The former probably apocryphal.
Interestingly I have recently watched a video of Feynmann essentially saying "I cannot explain it to you because you don't have relevant background knowledge" to a question of "What makes magnets repel or pull each other?". Which agrees with the latter.
Of both quotes the latter is definitely closer to the truth.
Then there is the corollary: a topic is shallow, if an expert can explain it to a layman before the layman loses interest.
I've been working with experts on highly technical topics most of my career. They can explain the big picture to a layman just fine, but if the layman asks something within the actual scope of their expertise, it takes a long time to get there.
True experts can understand from the layman's perspective and tailor the response to that level of understanding.