I taught my partner to take photos without auto-everything mode. She asked me to, I'm not on some evangelical quest! She couldn't understand that F-stop is F-stop, regardless.
It took one loooooooong session with old manual lenses, auto lenses, moving the diaphragm lever on the lens with my thumb and changing lenses without changing camera settings for her to "get it". It's just a number, but a very important one.
To me, it's one of those "penny drop" items, once you've grasped the principle it's very simple, until that point, not so much. I think my explanation was lacking, not her ability to learn. I had no-one to teach me, save library books, a Praktica film camera and dirt cheap postal film development to allow me to experiment. I've included a couple of old negative scans from the MTL5 and Pentax 50mm - these show me working out what shutters and F-stops did. There were many worse attempts!
Once you understand how shutter speed and F-stop work together, then you can understand how ISO also fits in, and about DOF and hyper-focals. At that point, you can operate any camera, film or digital, and your concentration is left to the important thing - finding the picture and taking it.
We may not shoot so much onto film and plates any more, but the fundamentals still apply.