Why marry?

[AFTT47]

I think of part of the problem in my mind as a sort of Fairy Tale syndrome, where super religious young people marry their prince/princess, then wake up with a real person.

I would say this is true for everyone, not simply religious people. The whole idea of the perfect mate is largely unrealistic. Human beings are much more complex than swans. Even if two people are "perfect" for each other at 20, expecting they will be the same at 60 is folly. People grow and change. The chances of any two people growing and changing at the same rate and in the same way is remote.