YOU SAY "Maybe PR only applies to computer-like person. Or maybe some people are born with the potentiality to learn and use it well, while others aren't."
Thats a bit like saying not everyone can learn to tie shoe's, if you or anyone else makes the chunk size of any learning task, then you and anyboby else who cears to make the effort can learn most anything, you can't learn to spell if you don't brake the words up, learning to PR, is a case of building skill on top of skill, a bit like building a chain, one part of the process links to the next and so on.
a note on the word "tried" there is on tried there is only do and not do, if you tried to open a door, it means you have failed, you can't fail, you can only create a leavel of feebback, that tells you that some parts of what you are doing are working well, and other need to be adjusted, I started out with Pr many many years ago, 1994/5 and at that time I was a very poor reader, with dyslexia and ADD/ADHD so my mind would run away with it's self, and it was hard keeping up, yet I just kept on keeping on, now I pr really good, and find it hard some time to read in a narmal way, ie, word for word, yet it as help me learn so many things, and keeping my attention on the point that matter to my learning task, so as you have a natural smartness that as been givn too you, maybe you might consider, allowing this smart arse, leand you a few thoughts.
2 Be speicfic with your purpose
3 make notes of any questions that come to mind
4 You can do the Pring in and out of order, now before some says you can't YOU CAN,
5 Give your self enough time to pay a litte more time to go over, anybits of info that your mind might pop uo from time to time,
6 carry a little note pad with you all the time, so if something comes to mind when your out and about you can jot it down, if you don't have a note pad with when this happens, if you have a cell/mobile phone use the text funtion to take the notes.
7 sometimes it best to do lots and lots of little passes, just stop at what seem at ramdom places on the page, think of a quick question and see if what you read, fits with the question, I find 7 out 10 times, this works for me.
8 keep reminding your self of what are your goals for learning what ever you are learning, how are you going to use the new learnings.
9 recap you notes, key words, and purpose and tell your self that you will find learning anything new to be easy.
AND IT WILL BE.