I'd say it takes a certain curiosity to make all of this work. Like the other day I read up on SQL indexes and how they work under the hood. I didn't need to, I know what they do and what I needed them to do. But there was this itch when I realized that I don't know how they do it.

And there are many such things depending on the specialty. I'm in web dev and often the work I do is very detached from actual communication protocols and such. I see devs that don't even know how cookies work in an MVC app. And while it's not necessary, it helps a lot to have basic understanding of what happens when you call an API, how exactly HTTP differs from HTTPS, even what happens at TLS and TCP layer of things.

I consider myself a generalist and it's this curiosity that makes me adequate in many different subspecialties. I'm not the best at things, but I can get shit done myself when I need to.

I like this answer the most.