Many teens entering adulthood look at problems and mistakes of the generations before them and say "That will never happen to me." Bad marriages/relationships/parenting, money issues, health. Some things are beyond anyone's control, like illnesses. And most do not go into a marriage anticipating that they will be in the percentage doomed to fail. But the unforeseeable can happen no matter what. Post advice or a fact you have learned along the way through experience or observation.