This means that rereading is a no-go strategy for learning.
So how can I learn to read?
Take notes. Apply information as you come across it. Learn how your brain stores information and take advantage of that. Learn things as though you're going to teach them.
When we reread we tend to skip things that we think we know but don't.
What kind of material you want to learn? How long is the book? The tricks to learn each subject may be different.
Use a lot of paper and pencil (and a trash bin) to copy the proofs and the solution of the solved problems. (Bonus points if you can think variants, and prove the variants or understand why the variants are false.)
Use more paper and pencil to solve the exercises.
For the research papers, the problem is that the style is too short. You must fill the blanks, and sometimes they are not obvious. In the first papers of a subject you may have to go very slowly, perhaps one page per hour or even slower. Copy the proof and fill all the blanks. [Note that the introductions and conclusions are sometimes too optimistic.]