That "knack" could also be an affinity for tinkering & working with your hands. My brother is a self-taught auto mechanic because he is really interested in car

That "knack" could also be an affinity for tinkering & working with your hands. My brother is a self-taught auto mechanic because he is really interested in cars. Give him a free weekend and he'll rebuild his engine for the heck of it. When we enjoy something, we do it often. When we do something often, we get better at it.