I fell under the "under 21, get married fast to the first guy that likes you" group. I was also in the group that fell under, " oh shit that was stupid, now I am married to an abusive jerk, after a couple years of doing it god's way and not working, I think I will do this MY way" group.
I was 20 when I got married and at the time that was almost old. I think I know of only one person I was friends with whose marriage is still together. Everyone else got married at 18, had a kid, broke up and now living in their parents house with their kid.