TL;DR - Don't re-read presentations. Drop the materials into AI, have it generate tests, answer them, get corrected. Then explain the topic to a friend.
The best way to learn theory in CS is simple: you need to feel friction. If you're passively reading the presentations and books, you're falling behind.
What to do instead: drop the lecture materials into an AI - Claude, Gemini, NotebookLM, whatever (I mostly used Claude Code). Have it create tests from them: multiple choice, open questions. Answer them. The AI tells you what was right, what was wrong, and what to do better.
Then test yourself again. And again.
The final lock-in: talk about the topic with a friend and explain it to them. If you can teach it, you know it. The information retains far harder once you've said it out loud.