My mother and father are both twice divorced, and only now late in life have found enormously happy relationships, like, relationships they never thought were possible after the first marriage, and indeed, now that the stress of trying to collectively but not really raise three kids is gone, my mother and father are kind of friends, and my mother adores the lady my father is about to be married to.

The fact of the matter is, a previous relationship failing doesn't have to mean anything. You can grow as a person, fix previous faults, learn how to interact with people who you don't 100% mesh with. As most things in life, it matters the effort you put into it, and then you can always get very lucky.