For what it's worth, I think I finally figured out what I was doing.
Depending on where you are I guess, this will be either utterly "duh" tautalogical, or (like it was for me) a slowly-dawning "Eureka!" moment.
Unconsciously in my head, I was building a 3D model.
In that model, because of my vision and life experience living in the physical world, I knew where the target was in relation to myself and my reference frame.
In that model, mostly because of body mechanics but also a bit of peripheral vision, I knew the orientation of the arrow in relation to myself and my reference frame.
"All" I was doing was orienting the arrow in that mental model to point at the spot of the target I wanted to hit.
The bow was irrelevant, except as an application of force along a particular vector.
Aim was irrelevant: I wasn't keying off any particular aspect of the scene.
Heck, if I had the arm strength, proper stance and anchoring would be largely irrelevant.
ALL THAT MATTERED was that 3D model in my head, and the orientation of the arrow on all three axes as it related to the target.
When the arrow was properly aligned to the target, it was time to release.
I'm sure with more experience I could learn to correlate approximate force of the bow with weight of the arrow, gravity, etc. But for now I think I've got a pretty good thread to pull on. Most importantly, now that I know
what I've been doing, it's not a mystical magical voodoo beyond my prediction or control. Which means I can have some confidence that I actually can learn to do this on demand.
Woo!
Persona: Aerlinneth, Dúnedain of Amon Lendel c. TA 3010.