When I've formally taught hunter safety classes to youth, it's always been kids who've grown up around and have already been using guns whom I've instructed. Most of them recognize a "safe" rifle or shotgun. So one of the first things I do it show them my 870 and ask them to inspect the safety to make sure the shotgun cannot fire. After examining and affirming that it is safe to handle, I grab the barrel and thump the butt on the floor whereupon the hammer disengages, firing the primed-only shell which was previously placed in the chamber. It gets their attention. The point is to teach the fact that no safety should be counted on. Secondly, it is a point from which one can teach the idea that there is very little to prevent a firearm's sear from disengaging - and all it takes is the smallest particle of ordinary debris common to the outdoors to make the usually adequate sear engagement no longer safe.
I'm sure those who don't have an awareness and appreciation for their guns' mechanisms probably traipse along with greater confidence in their infallibility. That is the precise reason I almost never engage a safety.
Sometimes, the air you 'let in'matters less than the air you 'let out'.
