People always say you "reiterate and learn", but if you one of your videos blows up out of luck and you get monetized. What do you learn?

I doubt the learn part here is "just get lucky". So I'm asking those who took months or maybe even years to get monetized while regularly or consistently uploading. What did you reiterate and learn from? (How do you spot these mistakes or even know they're the gaps you should learn in order to move forward?)