Firefly, yes, that's where my example of a Yak zero airspeed with no stall and seconds later a stall at 140 knots (both in the same manouvre) came from.
But I wonder if the average non-flyer (i.e. a low hour stude) would gain anything from such a demo? I suspect not.
Experienced pilots, however, should know this stuff. It seems many don't.