So like, the whole concept of this manga is that he doesn't have any natural talent and just puts a lot of effort into learning and doesn't accept established "facts" such as skills only being usable by those who have the appropriate classes. But he also seems to be capable of memorizing the contents of entire books just by speedreading them as well as manually construct magic formulas in his head (not to mention that he become the strongest swordsman in the world at the age of like 15 or something). So I mean, clearly he's a genius, isn't he? So it's not like it's ONLY hard work and effort that got him to where he is.