Inferential Distance between two people with respect to an item of knowledge is the amount of steps or concepts a person needs to share before they can successfully communicate the object level point. This can be thought of as the missing foundation or building block concepts needed to think clearly about a specific thing.
In Expecting Short Inferential Distances, Eliezer Yudkowsky posits that humans systematically underestimate inferential distances.
...And if you think you can explain the concept of “systematically underestimated inferential distances” briefly, in just a few words, I’ve got some sad news for you . . . – Expecting Short Inferential Distances