You've been going along, happy as can be. Things are just great with your spouse and you think, "Wow, this is terrific." And, it is, but you start feeling antsy and a little anxious although you can't see any reason for being anxious, so you just push it away. And then something happens—one of you does some little thing: he forgets to take the trash out, you leave your shoes wherever they happen to drop off your weary feet and WHAM! Suddenly you're in the middle of World War III.

Things calm down and although everything is shaky for a while, the relationship pulls together. You’re both happy and once again you think, "Hey, okay, how about that, we're going to make it!" As things get going great again, you start feeling a little anxious and sure enough here comes something that in hindsight seems so idiotic, but there you both are back in the middle of World War III.

Dismally, you conclude either that you are a failure—no way can you have a good marriage—or that the whole idea of marriage is a failure, or that your ‘til-death-do-us-part mate is a failure. However you look at it, all you see is misery. Whether you stay in the relationship or get out of it you're one unhappy camper.

What to do? Well, first notice that maybe you're wrong. Maybe there isn't failure here at all. Maybe the whole problem is you're not used to success. Most of us are far more familiar with what to do in the event of a disaster than we are with what to do in the face of happiness. How much training did you get in school on, "How to deal with a successful marriage and the maintenance of happiness?" How many articles are devoted to this idea? How often did your parents lecture you on the subject? How many seminars? Billboards? TV shows?

Oh, maybe an article here and a show there, but the vast preponderance of the emphasis in our culture is on problems; what to do when your relationship is on the rocks? Certainly that is extremely important. But you also need to know what to do with the success and happiness of your relationship, otherwise as given in the examples above, when all is going wonderfully well, you will get anxious and somehow re-establish the old status quo by making a mountain out of the next molehill that comes along.

Enter the "pull of the familiar." We are always more comfortable with what is familiar to us than with what is not. That is why people often stay in unhappy relationships; the hurt you know is less frightening than the potential hurt you don't know. You know what to do when your marriage isn't going well: you try to communicate better, read self-help books, talk it over with friends, see a therapist, you write in your journal, etc. What do you do when your marriage is going well? Good question. Certainly you enjoy it, but how do you grow it from there? How do you go from happiness to greater happiness?

In a word: carefully. With love and patience. First value what you have, then look for more and more to value and appreciate, both within the marriage and with your spouse. The quickest way to destroy a marriage is to stop appreciating it. The surest way to enjoy a successful marriage is to find more ways to appreciate it, and to do so with increasing depth. Deliberately create opportunities to explore the wonder of the relationship, to explore the fun of it. Set aside special times together, commit to those times, make plans to do special things together and give the relationship importance. Treat your spouse special all the time, express your appreciation of them openly and often. Never take happiness for granted.

Does this mean ignore whatever problems may arise? No, of course not. But don't ignore the happiness either. When you feel that funny anxiety of, "Things are going too well, when's the other shoe going to drop?" work with yourself, know your anxiety is simply coming out of the unfamiliarity of happiness and that there doesn't have to be "another shoe."

Noelle C. Nelson, Ph.D. is a psychologist, consultant, speaker and author. Her most recent book is "The Power of Appreciation in Everyday Life" (Insomniac Press, 2006). Her new book, "Your Man Is Wonderful" (Free Press) will be released in January 2009. For more than a decade, she has helped people live happier, healthier lives through appreciation—at work, at home and in relationships. E-mail: nnelson@dr.noellenelson.com, website: www.noellenelson.com.