hit the nail on the head

"...[you have to] be able to put [someone] else's feelings and desires above [your] own. And unless you can do that more times than not, day in and day out in a relationship--- much moreso in a marriage-- then both people are doomed for unhappiness, and the marriage is doomed for divorce. Doing nice things and saying nice things for and to your partner are not things that are contrived or done out of being "expected to do it and say it." It comes naturally and freely for someone who truly loves another person and wants to spend the rest of their life with them...if both people don't have a genuine, mutual desire to put his/her partner first in thought, word, and deed then one person is going to feel frustrated and constrained and the other is going to feel hurt, cheated and lonely in varying degrees from time to time until after a few years the gaps between the "feel good times" and "the bad times"become narrower and narrower and unhappiness gradually turns into resentfulness and bitterness..."

-Anonymous

wow. very very insightful.