Comment by exmadscientist

When I taught I often thought of it as explaining in a spiral: first I must go around the concept, before I can dive in to the concept. Going around gives boundary and definition to what I'm talking about, allowing people to place it in the proper spot in their mental framework and to relate it with other nearby things. It also gives some motivation for what this thing is and why they should care. Then when that is done (and it does not take long), the details can be discussed, and they're easier to communicate because people are primed to receive them.