Competitive quizzers are not people who read more. They are people who practise retrieval systematically, track what they get wrong, and deliberately study the areas they find least interesting.
They map their gaps first
Before studying anything, a serious quizzer finds out where they lose points — usually by playing a lot and logging the misses. Almost everyone discovers their weakness is a category they had quietly been avoiding. General reading feels productive and mostly reinforces what you already know. Targeted work on your worst category is unpleasant and is where the points are.
They practise under time
Knowing a fact and producing it in four seconds are different skills. Champions rehearse with a clock because the clock is what they will face. This is also why they answer out loud. Silent recognition is far easier than spoken recall, and only one of those wins a round.
They study lists that repeat
Quiz questions are not random. Capital cities, Nobel laureates, Oscar winners, chemical symbols and Olympic hosts come up disproportionately often, because question writers draw from the same wells. Learning one such list properly returns more points per hour than any amount of broad reading.
The habit that separates them from everyone else is the least glamorous one: writing down every question they got wrong, and going back to it a week later.