Academic subs

Can you guys PLEASE recommend me academic subs that have worked for you well? Only recommend me subs that have worked for you well. Like, something that has made you smarter, disciplined, motivated to study and has made your grades skyrocket.

I have seen a few people saying that their grades got better with certain subs but their grades just went from around 80% to around 90% or 95%. Like, it seems their grades are already really good and it could just be a genuine improvement from their own effort rather than the subliminal y'know?😭😭

can i please get recommendations of subs that really genuinely worked?? something that made you super smart. like i want my grades to go up but i want to genuinely be good at the things that i am studying too; rather than just having good grades.