Craftsmen tend to develop a heightened sensitivity for the nuances of their tools.

For instance, a sensitivity to the sharpness (or bluntness) of edges; to the weight and balance and texture in one's grip; and to that satisfying thud, crunch or bite when your tool does its thing correctly.

All domains may apply: consider the tailors who touch fabric with their hands, professional drivers who can taste the grip of their tyres on different roads, writers who innately see changes in phrasing and tenor, and so on.

The Caps I Wear

I relish the same feeling as I wear three distinct caps:

• As a musician: When I run guitars through audio interfaces/layers of VSTs, I feel latency acutely. It's impossible to explain, but I can perceive latency falling behind even in the lower milliseconds. Perceiving the existence of latency is important, because my guitar playing can take on a wholly different character when there's lag.

• As a programmer: When my computer performs responsively, I feel like it's predicting my every touch. And when it does not, even the slightest lag and UI non-responsiveness makes the computer feel like I'm running my fingers by a jagged blunt knife; the keys hurt me to touch.

• As a lawyer: When I come across legal arguments that flow, reasoning clicks into place seamlessly. It feels like a peaceful stream of insight. But when premises misalign, or the syllogisms break, I feel as if I've stepped onto a loose stone in a cobbled path. I sense something missing immediately, even if I can't articulate it until I conduct a detailed analysis.

So I've grown to believe that expertise is not just accumulated ability. Rather:

• it's more a test of how honed you've become in a particular domain;

• you 'arrive' at it when you can feel more acutely than others whatever impedes or causes a lack in the expression of your ability; and

• you can adapt properly, and quickly, to that change in perceived stimuli.