So here goes: Your quality and purpose of life is not determined by whether or not you date or get married.
But, take a moment to think about what life is like outside of your hometown. If you still want to be with the same person after you meet a smarter, better looking, funnier version of them, you might be obsessed with your high school bf/gf.
This means people are willinging to get into a relationship with someone they might not have given a second look in the real world (high school is not the real world, silly).
When you're in this high school dating pool you're basically working the law of proximity which says, objects (or people) that tend to be near each other often group together.
I do not intend to defend a certain set of rules, or refute any.
Neither will I pretend like I have the best advice, since I am not even married.