Tim Bray shows us the philosophy we should all have when explaining things to others:
... when I explain something to someone and they don't get it, that's my problem, not theirs.
Then he asks for discussion about how to explain his topic effectively, but he doesn't allow comments on his web site
His point is well-taken. The way you explain something is entirely dependent upon your audience, and is contingent upon their background and experience. If you're not explaining things in a way your audience can understand, that's your fault, not theirs.
Explaining things in a way your audience can understand often involves leaving out information. Going into too much detail is often a problem people (including myself) have. Programmers and other technical people in particular like to show off what they know, and revel in the little details of how everything they're explaining fits together. Piece of advice: It's great that you know what you're talking about, but when explaining it, think about your audience, not yourself.
Sometimes, however, it's simply not clear what your audience will be able to handle. How far back do you have to go to make something clear to someone when what you're explaining depends on so many other things your audience isn't familiar with? That is often the hardest part of explaining, not getting the details right.
One problem I often have is that I don't want to lie to someone or be misleading, so I often feel the need to go qualify many things as I go along. The problem is that the person probably doesn't know the difference or even care, and would be better served if I did "lie" to hide unimportant details. That's a hurdle I have trouble getting over.
Surely it's sometimes their problem. I mean, someone could explain something incredibly well, but the other person might not get it. They could simply not want to understand.
But I know what you mean about not wanting to lie to simplfy things so they make sense. I think the solution lies in having to spend time with children. Then you end up lie/simplfying all the time. I know I do. Like calvins dad out of calvin and hobbes, only less so. "How does a light bulb work?" "magic" "didn't you say thats how the vacuum cleaner works?" "right. they're both magic"