When I started coaching Track and Field, I suddenly become quite interested in how the human body works.
And the more interested I got, the better my teams got.  (Or was it the other way around?)  

And then, when the chronic stress of coaching one of the top division teams in the state year 'round jump-started
an autoimmune disease that had previously been under control and my life got very painful, I became yet
more interested.  Because pain is even more motivating than competition, at least for me.

So anyway, I come by my expertise honestly - it became a necessity.  One of my favorite quotes, from the
TV show Barney Miller, says "The years force a certain amount of wisdom on a man, ...