Agreed. Let's turn this into an operational test. If you can come up with a way to make it rain in your kitchen, you understand the phenomenon. (Compare Hacking's "If you can spray them, they are real.")

It doesn't really matter then what language you use. Some people might use "condensation" as a fake explanation, and that's no better than "sky spirits", which I guess was bgrah449's point.

Catching yourself in a fake explanation is trickier than it might seem. As my kids reach a certain age I find myself dealing with questions like "Dad, what's causing the rainbow?" You learn to cue on a certain tone of voice. "Well son, it's because of refraction." Ouch, too late, failed to catch that one in time.

"Well, it's....", and trailing off... "Buggered if I know right now, actually. It's something about angles and the shape of water droplets, and if you ask me again once I've stopped the car we'll draw a diagram together and see if we can work it out; the basic principle isn't too hard but there's a twist or two, like that second rainbow."

Better now. And I know that I don't really understand refraction; the geometric part of the optics here I know I can derive from scratch with what high school math I have left, but I don't have a good enough grasp of electromagnetism to explain why the refractive index varies. Even to a dedicated reductionist, all explanations are ultimately "fake", at least until we have a Theory of Everything and a mind capable of grasping the entire chain of its implications up to the rainbow; don't hold your breath.

But there is such a thing as "good enough".