Expertise

Malcolm Gladwell, in his book Outliers, famously wrote about the "10,000-hour rule". As he explains it, when most people exhibit virtuoso skill at something, it's less because they have preternatural talent (though there's that, too) but more because they quite literally put in the hours. In this regard, it so happens that 10,000 hours is more or less the amount of time it takes for a person to become an expert at something -- proving that there is some truth to the saying that practice makes perfect.

In a similar fashion, you could also argue that Expertise is the result of the steps that you take to go from unconscious incompetence to unconscious competence:

This is very intuitive to grasp:

1. Unconscious Incompetence. A state of obliviousness. You're blissfully unaware that you're bad at something. Or, to put it differently, you don't even know that you don't know.
2. Conscious Incompetence. A state of self-awareness. You may continue to stumble and struggle, but the difference is that you realize you're not as proficient at something as you would perhaps like to be.
3. Conscious Competence. A state of improvement. Aware of your shortcomings, you've started to gain proficiency, even if it takes plenty of effort just to do things well.
   
4. Unconscious Competence. The state of expertise. You're good at what you do; so good, in fact, that it comes effortlessly.

Regardless of how you see it, the simple fact is that achieving even a little Expertise takes a lot of effort, beginning with the realization that much can stand improvement. In that respect, it turns out that Socrates was right: wise is the man who knows that he knows not.

[Note: This missive -- the diagram, in particular -- was inspired by Atul Gawande's New Yorker piece about coaching for professionals, which is a great read.]