When you say they didn't work, what does that mean? Opened 10-20 and they all opened as a PDF or a webpage(albeit some don't have HTTPS certificates).

The book Make It Stick by Brown, Roediger and McDaniel is helpful. tl;dr of it is:

- lots of low-stakes quizzing and practice

- spaced repetition

- reflect on what you've learned and what you could do better next time, and apply these lessons in different contexts

- interleave practice of different but related topics

- try to solve a problem before being taught the solution

- distill the underlying principles to different problems

- remember that if learning is easy, you probably aren't engaging you brain very much

This will help streamline the process, but obviously there's just a limit to what you can take in.

Do you wish you had time to learn about them? Or do you wish you just knew them? Having them uploaded to your brain might make you know about them, but is much different from having time to learn them. This is important if for you, like for me, learning itself is a large part of the enjoyment

Are they not available at archive.org or YouTube ?

Search for "computer science". I found several CS50...