Since not getting married or reproducing have both been mentioned quite a bit (and are for sure my top two as well), I’ll go a bit further down the line.
I’m really glad I stopped wearing makeup at 15., and never started again. I’m just shy of 40 now and on the rare occasion I do wear something, for a wedding or something, everyone gushes about how nice it looks and that feels good, but I am thrilled I don’t waste my time or money on it every day. My skin looks 10 years younger, and I’m not financially contributing to marketing campaigns that make people self-conscious about their appearance.
(If makeup is your jam that’s cool, zero judgement, I’m just very lazy and don’t care how I look enough to spend money and time on it)