Yeah, but competitive quizzing is really no different from any other type of competitive activity. If you want to get better, you have to train / practice.
So, if you're a competitive quizzer, you would surely know that certain questions come up over and over again - we call them "chestnuts" - so you then have a choice: learn them and you'll become a "better" quizzer, or don't and you won't.
E.g. all quizzers know the US state capitals. Over the course of any given year, we have no need whatever to retain these facts, other than to answer correctly next time we're asked a question about them in a quiz, so we've all taken a short time and learnt them. Without getting into an argument about Puerto Rico, there are presently only fifty of them, so how hard could it realistically be?