Writing is one of those things nobody really understands. We can build devices that shoot our thoughts and words off across great distances. But we can't really understand how we form those thoughts, or how they're rebuilt in the mind of the listener. We're in the middle of some information age -- be it evolution, revolution or death spiral -- and somehow we still dawdle around wondering if words came first or images or meaning. Sooner or later you're right back praying to the muses, just like the Greeks a couple millenia ago.
Things get no easier when you try to build a life around writing. You think you get your head around it, then it humbles you again. You dare to 'teach' it -- and wham, there's always something more. You foolishly rush into the profession of writing, and there you are with your toolbox full of plot and character and elements of drama, standing dumbfounded by the monster in front of you. Writing is like love. It pays to recognize ahead of time that you'll be regularly dumbfounded.
I've settled on the comfortingly obtuse idea that our brains are basically quantum machines. We bring things into being by observing them, by making choices about them, by pointing our intention at them. It explains to me why a character that I've constructed roughly out of a couple basic elements can just start chattering back at me one day. There's a real act of creation here. It doesn't matter that the character isn't standing there in front of you. Apparently we can't directly experience seven of the ten major dimensions anyway. What's another protagonist or two?
There's a lot of research implying that as far as the brain is concerned, dreams and memory are pretty much the same as actual experience. "Show, don't tell" indeed.