I would venture that, in many way, marriage is a practical institution, held together by practical considerations. There is a good deal to be said for negotiating a mutually beneficial long term contract with another individual for the facillitation of mutual prosperity and stability. That being said, it is possible that marriage comes with a set of unreasonable expectations as well, expectations that humanity cannot be expected to meet based on evidence. Would it not be wiser to modify our expectations to avoid all the disappointment rather than continuing to hold ourselves to a set of criteria that historically we have demonstrated ourselves as unable to meet?