I think the reason why Richard Feynman was such a great orator is that he could overcome this gap to a certain extent.
Matt O'Dowd on PBS Space Time also has a great way of breaking down really complex theories (especially if you watch a set of presentations in order).
[PBS Space Time (YouTube)] https://www.youtube.com/channel/UC7_gcs09iThXybpVgjHZ_7g
This is something I've thought a lot about as I've tried to teach basic skills at $corp to smart people with relatively little formal comp sci or programming experience.
It led me to write two books using the Hard Way method:
http://learnbashthehardway.tk/learnbashthehardway.pdf
http://learngitthehardway.tk/learngitthehardway.pdf
It doesn't assume zero knowledge, but it's so hard to know how to pitch. What I like about the hard way method is that typing stuff out forces you to engage the material and encourages self-learning through the topic.
I tried to teach my girlfriend programming once. She understood stuff that took me years in a few days.
When teaching, I remembered how hard concepts of variables and functions really are. It's really hard to explain it to someone.
I always liked people who were very smart but without losing touch with simplicity.
This is my prime concern when teaching and writing. Other terms for this I've seen is Expert Blindness and Expert Blindspot. A related term I've made up is Cognitive Empathy; ones ability to overcome this curse.
I've struggled a lot myself in school, and I think that had something to do with this.
With my current experience, just about any textbook I pick up and start reading, I can often pinpoint a lot of issues in the text that has this problem.
sometimes when flustered and tired from writing code and dealing with complex issues I access this, for humor and humility, for me.
https://simple.wikipedia.org/wiki/Main_Page https://www.reddit.com/r/explainlikeimfive/
In the same vein: https://www.ribbonfarm.com/2010/04/14/the-gervais-principle-...
Keep in mind the converse as well, when negotiating. i.e. you don't want to inadvertently leak information by assuming they know as much as you do.
He that gaineth knowledge, gaineth grief, for in much knowledge, there is much un-happiness.
That is the curse of knowledge, the more you know, the less happy you are.
Today they say "You Can't Handle the Truth", now many schools are saying the 'truth' is just a tribal crutch.
It used to be simple pure Epistemology was factual truth such as "2+2=4", now somebody will tell you otherwise.
"An educated man is somebody that you can explain your philosophy too, and he will not punch you in the face".
Knowledge, Tolerance, Understanding are all lost, but never mind, we can still toil are lives away for the almighty US-DOLLAR ( faux fiat toilet paper, another unworthy god ).
And this is why I used to joke with my tutorial partners at Oxford that the more titles someone had, the worse they were at teaching. I did find that the best tutors tended to be ones who were PhD students, with the content somewhat fresh in their minds.
Part of it is that when you become very senior, you start to become an administrator of a little research business, rather than a teacher.
Another part is that once you've internalised something, you cannot fathom not knowing it. Imagine not knowing what the complex plane is, and trying to explain it to someone who only knows what the real numbers are. Your explanations just won't make sense until you can place the real line inside the complex plane, and shepard the learner to the same state.