I mull over, pretty often, why it is that newbies think photography is hard. First, of course, is that they are told by the slightly-less-new that photography is hard. Second, of course, is that the explanatory information easily available is terrible.
There's more to it than that, however. Let us suppose that someone explains what Aperture means. There's these leaves, they make a hole, the hole is bigger or smaller. And then with the smaller hole there's more depth of field. It is natural at this point to suppose that the connection between these two things is obvious. One is stated immediately after the other, without explanation, but with a clear statement of cause and effect. Why, why don't I get it? What am I missing? Why does the smaller hole make more depth of field? the neophyte might reasonably think.
In fact the connection between hole-size and depth-of-field is extremely complicated. I know how to draw the pictures for an ideal lens, and, if I work at it pretty hard, I can grasp the details for a moment. And I have a PhD in mathematics. The fact is that all you really need to know, and all virtually all photographers actually do know, is that the bigger the hole, the smaller the number, the less DoF.
Similarly, shutter speed and motion blur; ISO and noise. Similarly, I suspect, virtually every technical detail about photography.
The more brazen neophyte might ask for details on the missing connections. Most photographers have a vague idea that they understand the connections, because they are in fact second nature to us. But in reality we do not understand them. The result is likely to be some muddled and confusing mess that sounds sort of like an explanation, but is not, which leaves the neophyte much worse off Gosh! I don't even understand the explanation. This must be super hard! How am I ever going to learn photography?!!
We emphasize the technical details over the visual effects, and because the technical details are complex (and we don't understand them ourselves) we often leave gaps in explanations we give. This makes the technical details appear more difficult than they are, when in reality they are irrelevant.
That's worth repeating:
The technical details are irrelevant.
Technical detail is important if, and only if, grasping it allows us to quickly and more thoroughly understand the real topic we're interested in. Sometimes a few simple principles can open up an entire discipline, once well understood. Photography is not like this, for the most part. The details of how a focal plane shutter work help us to understand why using flash above the sync speed looks like that, and pretty much nothing else. If knowing about the dragging slit opened up vistas, and explained a dozen different things, it would be worth knowing. Since it explains one (1) actual thing you're likely to run in to, it's pretty valueless knowledge.
What we ought to do is point out clearly where there is a gap, and that it is a gap, and that it doesn't matter. Indeed, I think it is worth leaving out the technical details entirely.
If the aperture number is smaller, you'll get shallower depth of field. The closer the subject, the more dramatic this effect will be
is probably a fine starting point.