This is an interesting thread, primarily because it's fun to reflect on whether everyone's intuition rings true with my own experience.
I think folks who study "Human Factors Engineering" point to things like visual acuity (speed of focus, motion tracking), fine motor skills, and the ability to gauge the motion of objects through time and space as key elements in skillfully flying fighter aircraft. I'm sure the same attributes apply to us lowly Experimental GA pilots as well.
I don't consider myself an exceptionally skilled pilot, but my progression of experience hits on an interesting combination of topics already covered here. In chronological order over my lifetime, it goes something like this: Legos, wrench turning, R/C (cars, gliders, airplanes, helicopters), cars, mountain bikes, car racing, motorcycles, engineering, gliders, taildraggers, IFR, RVs, Stearmans (Stearmen?).
I think I've borrowed from experience at each step, and somehow, all of these experiences have crafted the ways I react to specfic situations. For example, knowing how to effectively use brakes on a high performance motorcycle directly translates to balancing the use of elevator and brakes in slowing a taildragger in a short field situation. Learning pitch control in a glider directly affects how one reacts in the first instant after a strong, unexpected downdraft in an RV on short final.
I also think a good sense of mechanical things is important aspect of flying an airplane, both in normal operations and in knowing the difference between an anomoly and an emergency.
I'm not sure to take away from this, but it does seem beneficial for pilots to have had a variety of experiences in mastering "kinesthetic" control.
Keep the conversation going!
Cheers,
Matthew