After that spoiler, here is how I learn things:
1. Get the difficult stuff and read through it as long as your brain can parse it.
2. Once you have the first overview, rest and visit the same thing next time.
3. On second attempt depending on the context: i. If it is problem solving: Attempt to solve problems (look at examples and try to establish relationship) ii. If it is theoretical: Note down the key assumptions, key steps, key proofs.
4. Until you are confident, loop 2 and 3.
5. After 1 month or so, you will forget what you have then, thus go back to step 1.
Yes, this is highly inefficient. I really want to break out of this loop. But the issue is I am so accustomed that my brain goes into this mode by default.
The result is I get my own version of understanding which may not be the actual true understanding. But it is as close as it can get (70-80%). So I am happy about it!