I used to watch coverage of awards shows and always be amazed that some of the actors/musicians had been in long-term relationships, whereas most of them seemed to only be able to have fairly short ones. I actually felt that the celebrities that did stick and work on their relationships had more integrity. And in a way, I still think that.
Romantic relationships are a funny thing. Although there are plenty of arguments on how love changes and advances or whether there is only one “the one” for each of us, the fact remains that relationships go through difficult times. Even the best relationships go through difficult times. And if you’re in that difficult time in a relationship, you are faced with a simple decision - do you work on the problems and try and get out of that difficult time, or do you end the relationship. Simply (and evolutionarily) put: fight or flight.