Being a marathon runner for years through adolescence left me lean, mildly muscular, but with knee injuries and still somewhat small and frail.
My girlfriend at the time was a national level rodeo competitor and I had to consistently deal with a cocky attitude from her male counterpart competitors. At that time it was important that I showed everyone what I was made of in a way that would better who I was as a person as well.... that is where it all began,

The desire to constantly better myself. You cannot ever, ever reach the tippy top. There is always a higher peak (figuratively).
As a great Nike ad once said, and what is now tattooed on my right shoulder, "Money doesn't wait atop the hill, glory doesn't wait atop the hill, all that waits atop the hill, is the top of the hill."