I did neither. What I did is basically say how much I enjoyed a certain activity (golf) and how much I prepared for it (all looking back after "retiring" from said sport). I began the essay describing the final putt I made in my competitive career (a fifteen footer

).
But if you don't want to do that idea, I think reflecting on an impact(s) would be significantly better than just listing accomplishements. This is an essay, not a resume. I know you don't have much room, but that is the challenge; you have to say a lot in a few words.