I had to choose between Ex and Uni at 18, and seriously regret it. We married at 20, and my parents did nothing to dissuade me at all. No-one seemed keen for me to study. It seems strange now, but my mother was planning to leave my father, and did so only weeks after the wedding. She told me that she wanted me settled and happy before she went, and me being married off, to her, was a better solution than me trying to study whilst worrying about her disappearance. She literally did disappear for well over a year.
During which time I inherited my little sister, dumped on me one day by my father. That was a really tough time, and I regret forcing him to take her back a year later. It made her feel very unwanted by everyone. I managed to track my mother down eventually and we did what my father had done to me - dumped my sister on her, by now aged fourteen. By then my mother had had enough of 'I want to be alone', so almost normal life resumed, but now I quite regret having hidden my anger from her quite so well. She wanted me married off, but her actions didn't exactly help my new marriage to go well.