However, the internal representation is not very good for transferring knowledge. It may be just a human thing, or perhaps it's a universal quality of knowledge, that the shortest explanations aren't very enlightening on their own. We often need some context for the knowledge to really stick. That is why we need the External explanations. The external explanation tells us how the thing connects to the rest of our world. It can tell us which problem the thing is meant to solve. It can reveal why the assumptions used, are exactly the assumptions needed. If the person giving the external explanation seems to be very vague and unsure, perhaps they themselves have not thought it through enough, and will not be taken seriously. A person who gives long external explanations however, is often extremely appreciated by their audience. I can't say the same thing about a person who presents long internal explanations. So there is also a lot of power in mastering the external explanation, both for personal and for social reasons.
I have presented a distinction between two kinds of explanations, and what they are good for. I hope these concepts are useful to you.