There’s a book “Feeling Good Together” that gives an answer for this: self-responsibility, and wanting to make your partner happy.<p>“What were the results? First, we examined the demographic variables. As it turned out, it makes little difference whether you're old or young, male or female, rich or poor. Education and religious affiliation were also unimportant. These variables appeared to have little or no impact on how happy or depressed the participants were, or how satisfying or conflicted their relationships were. The presence or number of children and the length of the relationship didn't seem very important either.<p>Some results were completely unexpected and hard to believe at first. None of our predictions about the pairings of husbands’ and wives’ attitudes appeared to be valid. There weren't any combinations that had anything whatsoever to do with the success or failure of any of these relationships. Instead, each partner's feelings seemed to depend entirely on their own attitudes, and not their partner's.<p>Which attitudes were the most important? Other-blame was by far the most important mind-set. People who blamed their partners (or people in general) for the problems in their relationships were angry, frustrated, unhappy, and intensely dissatisfied with their relationships. In addition, this mind-set accurately predicted what would happen in the future. Individuals who blamed their partners for the problems in their relationship were even more miserably unhappy three months later. Things were clearly going downhill for this group. In contrast, people who were willing to assume complete personal responsibility for solving the problems in their relationships, and who felt a strong commitment to making their partners happy, not only reported the most satisfying and loving relationships at the time of initial testing, but their positive feelings seemed to increase over time.<p>At first, I was disappointed by these results. The findings just seemed too simple. I had been convinced that certain patterns of interactions between husbands and wives would account for whether their relationships were successful or troubled. However, the study clearly indicated that this notion wasn't valid. The only thing that really seems to matter is this: Do you blame your partner for the problems in your relationship? If so, you may be in for a tough time. However, if you're willing to examine your own role in the problem and you feel that it's your job to make your partner happy, the prognosis for a rewarding, successful relationship is extremely positive—now and in the future. These appear to be the real keys to success in any relationship. It makes no difference whether the other person is your spouse, a family member, a neighbor, a friend, or even a complete stranger.”<p>Excerpt From Feeling Good Together. by David D. Burns, M.D.