I think the only exception in this case is she wasn't out getting laid in high school. She was more focused on getting good grades and lost her virginity at 18. I met her shortly after she turned 20. I didn't even fvcking choose this chick. She pursued me for two years while I dated and fvcked other women.
Dating younger women is going to increase the probability of getting one that's low mileage. Women who are still young haven't developed their own lives and routines at this point. What they end up doing is adapting your life and routines as their own. If you spend enough time with her, she will literally not know what life would be like without you.
I just can't stress enough how much of a waste it is to date older, high mileage women when you're looking for a LTR. If you're wanting to fvck and toss, you have a great big world of women to choose from. If you want a companion, you're going to have to work, filter, and ignore those who hate on you for "robbing the cradle".