I might get myself back up to nerdy-hacker level, but I don't think I'd bother with 90% of it.

So, big-O, command line, control flow, data structures and algorithms, linear algebra, why floats are not real numbers, orders of magnitude in processing speed and data access speed. Probably by watching some online university lectures and perhaps messing with an emulator for some moderately old hardware.

Probably not an actual language, even, given what LLMs can do, just enough to follow as pseudocode.

But professionally? I'd do something else.

Why not? We still have to learn how to write. AI is much better at it than the average guy anyway. It can do any style in most any language. No human on Earth is capable of that.

I would absolutely re-learn them, for the same reasons I learned them in the first place: I'm very interested in the subject.

Given the changes to the industry over the years, I wouldn't be likely to go back into it as a profession, but I'd certainly regain the skills.

I learned programming when it was a dark art, a decade before Stackoverflow was a thing. It was fun to learn and at a time when companies like Google were new and Facebook and Uber didn't exist. Now with AI it is both easier to learn, but for many use cases, unnecessary. There used to be a need to learn programming to build or maintain your personal website (the original reason I learned Perl), but there's tools for that now so you don't need to touch code. So to start fresh, I'd probably choose another field