@beperov People with high anxiety especially test anxiety can only succeed when studying the amount he does. I had that in my first year of university as I never had to study before university. The load with 5 classes and 15 midterms with labs, assignments and projects fucked me up. So I had to do what Maanabu does for a couple semesters to get my confidence back and learn how to learn as well as study.
Then there are many people who are not that particularly smart, but they work their butt off to reach the same heights as a person who needs to study little or non at all. We had a guy in grad school who had never shown up to class once, but he was a genius. His notes were better than the profs and he achieved the highest marks in all out classes whether it was undergrad or grad school. I do think people from asia are less likely to have good memories and require repetition to learn things which requires far more studying. This might be more apparent because academics are more valued in Asian countries which is why cheating is so rampant in India and China for example, though the chinese have a mantra or some shit about "doing all you can to win even if it means committing a grave sin."