I did well in my college math exams (top 5 percent of class) by just memorizing proofs and memorizing the methods to solve common problems without understanding

I did well in my college math exams (top 5 percent of class) by just memorizing proofs and memorizing the methods to solve common problems without understanding much of anything about what I was doing. The exams were very much hackable. I wouldn't be able to pull this off in grad level maths but undergrad it's feasible. It was a total waste of time though and I regret that approach, but I did what I was given an incentive to do (least effort for max reward)