As this is simply my theory, the outlooks expressed wherein are solely mine and do not reflect a degree of importance on the outcome of your life (unless perhaps you let it influence you which is your choice).
Love, today, is a forgotten word, a misappropriated word whose definition has been made twisted of its initial self. I have often watched the relationships of my friends and there parents and my parents and my parents friends and the people generally around me on a day to day basis to attempt to understand why, in this present day and age, so many relationships fail. It would seem that the conclusion is primarily based on these three factors: translation, religious piety, and the "unstoppable force-immovable object" paradox.
As far as translation is concerned it is not a failure of a language to translate efficiently across time, but rather simply a change in the whole definition as time has passed. In olden times love was more than a passionate embarking, there was too much responsibility and too little time for that (which is not to say it didnt exist). In fact, love, in many cases did not exist beyond the duties of a man and woman and the pre-arranged efforts of their parents. Today, with the degree of freedom, and albeit, to some denial im sure, the lack of responsibility held by EVERYONE love is more of an open field in which there are no limits, no duties and no boundaries. Love has become, due to this freedom, less of an engaging understanding and patience between two individuals and more of an obsession. These "obsessions" are not a patient relationship between two, but rather a successful attempt to create a host-guest connection to one another like leeches, always over dramatized and exaggerated, slowly sucking the life from each other.
Religious piety, in its day, was talented at keeping a relationship stable, admittedly because of the dominance of a man over a woman in that time (and before i get stabbed, if it were the other way around, with religion, it would have been the same, generally, in the eventual outcome). I firmly believe that most people do not quite yet fully possess the "freedom-maturity" to sustain a relationship without the supposed training wheels of religion, a sad outlook to be forced to embrace as it is, since I readily support religious freedom and the inevitable death of religion all-together.
Finally we reach the "unstoppable force-immovable object" paradox. Basically, most people are too unbending to sustain a relationship, being set in their ways and not capable of hearing, and let alone accepting the being of the other involved in the relationship. I kind of view it like our body to a drug which helps us. It is still foreign to the body and eventually the body comes to resist and reject that drug. If you only hear what you want to hear, then whether your counterpart does like you or is actually bending, it cannot work together, there must be given way for each member or both will fail.
Frankly, the lovey dovey obsessive bullshit is terminal. When a relationship is built on that bullshit, it is a common occurrence that one or both parties of a relationship cant accept the shift when it starts to fade to a more steady mature love. This has been, and will continue to be the death of many relationships.