I find posts like this simultaneously heartening and disheartening. Heartening because it means a lot of behaviors that are billed as "genius" or "high IQ" or what have you, might just be an individual unconsciously drawing upon years, maybe even decades, of experience that is layered on top of each other. The most obvious example of this, for our community, are actually codebases. The more you work on it, the easier it becomes to debug and figure out issues, sometimes without even looking at the code. When I was first starting out as a junior software engineer, I was shocked at how quickly some of the seniors could figure out bugs. I was upset because I thought that they might just be smarter than me, from a raw intelligence perspective.

But now, some years later, I've become that person, at least in my current company. I can debug issues pretty quickly, and my brain has a store of literally thousands of bugs and snags that have come up over the years, to the point where if someone says, "This feature isn't returning the right variables", I can usually point them to the fix without even looking up from my laptop. It sounds like magic, but really it's just localized expertise.

That's the heartening part--that all it takes is years to do it. The expertise is available to everyone, perhaps.

The disheartening part is the other side of the coin--what if you've started late? Does this mean that software engineers who start late, in their 40's or 50's, for example, might never reach the heights of software engineers who started early? That isn't true--there are examples to the contrary, I hope--but maybe they have a much steeper hill to climb. Or they have to figure out a different approach to getting up the hill, maybe combining years of experience from a different field.

I love essays about these topics: expertise, pattern-matching, your brain being shaped by what you do, etc. If anyone has any others, I'd love to see them.

EDIT: Some grammar mistakes.