I do agree, people get really confused easily about how it all works. For me, it's simple. I do not do complex electrical issues [ie, circuit board repairs] but when it comes to wiring, it's pretty simple.
I try not to enforce the believe that it is difficult/strange. Tell them it's difficult and they will believe you. Something that is difficult usually means you do not know what you are doing or how it works. That is ok, we all start there.
I would tell my techs that it's simple. It all starts and ends at the battery. If you can read a road map, you can read a wiring diagram.
The entire circuit matters. For some reason, people in the automotive industry seem to forget about the ground side. Therefore people rarely check things and because of that, many issues are caused because of the grounds.
Again, we all got to make it work in our head. I understand it can be complex, but I refuse to think it is.