Sometimes it's learned out of necessity. When I started riding, about 10 months ago, I was so weak I had no option but to use the gears and spin. I'm 54 years old and the owner of bad skinny legs
I think this helped me learn to spin smoothly. As an example today I did a 43 mile ride and my average cadence was 95. The max cadence I hit on this ride was 140. A dog surprised me and cought me on the 39 and I was too panicked to shift
It is learned best by practice.