Ask HN: How can I self study what a CS degree gives?

I already work professionally as a backend developer but I feel some days that CS graduate colleagues came to a very elegant solution that I didn't see in part because of what they learned in their degree studies. I know 'correlation does not imply causation' but I do feel it would be worth exploring.

What courses, outlines, books[0], guides, and resources would you suggest that could supplement a CS degree?

[0] I've heard of the Impostor's Handbook, bit I've also heard that it is flawed and not a good resource. If you have a different opinion, I'd be glad to hear why.