Built To Last?

As I write this I am in Surrey. Joy's youngest brother and fiancee are having an engagement party; all eyes are on a bright and prosperous future together. It's a happy time; they're on the brink of a journey that will shape and define them in so many ways. It's got me thinking about relationships in general, and what it takes to build and maintain them? I recall being told that if we spent less time trying to find the right partner and more time trying to be the right partner our relationships would be more successful. I can find no fault in this fairly obvious sentiment. Why then, do so many relationships that presumably start out with good intentions go so wrong? Well, if I were to hazard a guess I'd wager that a combination of selfishness and unrealistic expectations are probably at the root of things. It's hard to look outward, to put other's first, and to see beyond our own wants and desires. At the start of the relationship it's easy, all our passions are just so intense and immediate that all the arrows point in the same direction. It seems to me there's a transitional period to be negotiated, however, a time that starts from when those initial feelings ebb. An unspoken moment is reached when you have to choose to love rather than just swim in the chemistry of it. This is when relationships really take shape, and sometimes a tone is set that often leads to collapse. So what makes a relationship good? I'm no expert, but it probably has something to do with having two people willing to want each others highest good. Able to see beyond themselves and desire to see each other grow and become all that they can be. We've all heard the phrase the grass is greener, but I reckon that's nonsense. The grass is greener when you water it, and don't kid yourself otherwise. As couples remain together they change, which is unavoidable. Seems to me that its those that roll with this and embrace the change without seeing it as a threat that fare best. The person I am now is so changed from who I was ten years, or even five years ago. Why should we expect anything less? It goes without saying that trust and communication are pivotal, and I sometimes wonder just how honest couples are with each other about key aspects of their relationship? Do we understand them sexually? Or emotionally? If not why not? How can we be a decent partner if we've no idea what our other half needs from us? Again, this seems to me really basic stuff. Am I missing something?