Because I don't have a CS degree, I've been going back and brushing up on my fundamentals. It's been fun and I'm filling in a lot of gaps.
For C, I'm going through
@rtfeldman's Frontend Masters course (Frontend Masters is a lot more than frontend, btw), which is excellent. Richard does a great job. I know most of this stuff pretty well, but there have still been moments of "ohh, that's why that works the way it does" already.
(I also chose the best possible frame for his face lol ... you're welcome, Richard!)