The funny thing about 科 is that you get a bunch of uses corresponding (roughly) to science/sci- in English: 科学、科技、科幻…

…but then you also have 理科/文科/商科 where it's a general suffix for subjects?

Also, another fun-to-me thing: the way certain uses of 大 don't actually mean to imply a size/extent comparison, but just function as a note that Hey This Is A Big Deal (i.e. it's not like there's a 小会 that you need to distinguish this 大会 from XD)