This is not brain surgery.
Actually, I'd suggest that teaching ANYthing, from firearms to knitting to brain surgery, isn't brain surgery. Know the current skill sets of the learners, introduce a measured amount of challenge, allow the student to fill that challenge. The problem, as suggested in this thread, is the "bad advice" factor. Bad advice isn't measured amount of challenge. It's just plain wrong and doesn't promote the allowing of "filling the challenge".
It would seem expectable that in firearms, there is more of a "bad advice macho factor" than in other fields. I doubt that knitting instructors get side tracked with war stories when teaching their classes. But we (the gun guys) certainly do. We tend to get trapped into "Well I can do that so I can teach it" or worse "I had a really tough coach and I turned out ok, so I'll be an even tougher coach".
Sgt Lumpy - n0eq