The other day, after a talk to some graduate students at the Julliard School, one asked, "In The Dip, you talk about the advantage of mastery vs. being a mediocre jack of all trades. So does it make sense for me to continue focusing on mastering the violin?"
Without fear of error, I think it's easy to say that this woman will never become the best violinist in the world. That's because it's essentially impossible to be the one and only best violinist in the world. There might be 5,000 or 10,000 people who are so technically good at it as to be indistinguishable to all but a handful of orchestra listeners. This is true for many competitive fields–we might want to fool ourselves into thinking that we have become the one and only best at a technical skill, but it's extremely unlikely.
The quest for technical best is a form of hiding. You can hide from the marketplace because you're still practicing your technique. And you can hide from the hard work of real art and real connection because you decide that success lies in being the best technically, at getting a 99 instead of a 98 on an exam.
What we can become the best at is being an idiosyncratic exception to the standard. Joshua Bell is often mentioned (when violinists are mentioned at all) not because he is technically better than every other violinst, but because of his charisma and willingness to cross categories. He's the best in the world at being Josh Bell, not the best in the world at playing the violin.
The same trap happens to people who are coding in Java, designing furniture or training to be a corporate coach. It's a seductive form of self motivation, the notion that we can push and push and stay inside the lines and through sheer will, become technically perfect and thus in demand. Alas, it's not going to happen for most of us.
[The flipside of this are the practioners who bolster themselves up by claiming that they are, in fact, the most technically adept in the world. In my experience, they're fibbing to themselves when they'd be better off taking the time and effort to practice their craft. Just saying it doesn't make it so.]
Until we're honest with ourselves about what we're going to master, there's no chance we'll accomplish it.