I've gone from amateur punter to moderately competent athlete (think d3 college team, though my sport has no such metric), and my thought is this: The only way to get better if you've plateaued is to change something. The external reasons you fail matter only because they tell you what to change internally. I've done things that surely not more than 100 people have done, and I'm not, by any metric, in the top .000001% or whatever. I just decided to do them and fought hard, it really was that simple.

This also relates to my interp of the article. There's grinding/training and then there's "having that dog in ya". He's trying to remind people to do the latter.