Over the years, I have studied and observed such claims and reasons why an individual would be so gifted or knowledgeable in some field of studies, yet finds it hard to teach another person of lesser knowledge to understand it too.
Now that’s usually the case with most geniuses, and the reasons are now clear and evident. Most of them are crazy about gaining some accolades or some sort of name or recognition that they usually care less whether others understand or not.
Furthermore, one mostly finds it hard to break down a given concept to his audience owing to the fact that he/she hasn’t understood or mastered the concept well enough in the first place.
Hence the crude and vague solutions/presentation
Albert Einstein said:
If you can’t teach it to the understanding of a 12 year old, it simply means you don’t understand it well enough.
But you can actually teach someone to understand any concept if you become more interested in understanding the undying basics and rudiments of a subject or course; not just the Hows in doing certain things , but most importantly the Whys.
If you have deep desire, accompanied with love towards humanity, in this case, the person in need of your help or service, plus your years of mathematical wisdom and sophistication, you can always devise a means or methods to present an idea or concept in a more softer and accessible form.
A candle looses nothing by lightning another.