Teach good habits, and you do not have to reteach the same thing over and over again.
Over teach and you put off people who begin to think it is all far too much to take on board. That is the problem with a lot of formal education in electronics, and it is considered an old fashion approach.
You have a hard time teaching because you're having to reteach over and over again.
No you have an easy time because you only try and teach what the student needs to know. Ever tried to teach physics? That is indeed what you have to do, classical, quantum, atomic, standard model and so on. The same topics in increasingly more detail introducing new concepts as they are needed.
I find it much easier to teach someone how to do something if they never done it before, or have never had any instruction from anyone else.
Indeed, but that is the difference between training and education.