I met my husband, Peter, rather randomly, at all-the-Absolut-you-could-drink benefit for the Museum of Contemporary Art. We have often observed that had we not met that night, there is no particular reason to think we would have ever chanced on each other in the future, as we did not inhabit the same professional or social spheres. From time to time, I contemplate the fantastic possibility that had one of us ventured several footsteps to the right or the left that evening, my husband, my children and my home might be subtracted from the life I lead today. Counterintuitively, this counterfactual exercise in considering how much worse off I could be today brings me not distress, but pleasure. Then again, a series of elegant studies published in the Journal of Personality and Social Psychology suggest that my experience is not so counterintuitive after all.

The researchers show that people prompted to write about how a positive event may not have happened experience a greater uptick in mood than those prompted to describe the positive event.  In their most persuasive study, individuals in committed relationships wrote for 15 to 20 minutes about how they might never have met and connected with their partners. Others wrote instead about the reverse – that is, how they did meet, start dating, and end up with their partners. Several control conditions, which involved writing about one’s typical day or about one’s friendships, were included as well. The biggest increase in satisfaction with the relationship occurred not in the group that pondered the sunny beginnings of their union but in the “mental subtraction” (or “How I might never have met Peter”) group.

Why does “subtracting” a love, a triumph, or a dash of good fortune from our lives give us a bigger boost than simply savoring their reality? According to University of Virginia social psychologist MinkyungKoo and colleagues, the key mechanism is that thinking about how an event might never have come to pass renders it more mysterious and more surprising. Prior research has shown that surprise – and its cousins novelty, unexpectedness, variety, uncertainty, and unpredictability – is associated with more intense and more durable emotional reactions. In our own laboratories, Ken Sheldon and I have been testing the notion that surprise and variety can slow the rate at which people adapt to such life changes as buying a new condo or hybrid, marrying Mr. Right, or earning a coveted promotion. Any event or activity that yields novel and frequently surprising experiences and opportunities is likely to capture our attention and trigger frequent memories and thoughts about it. Surprises entice our attention and compel us to explain them, thereby maintaining the freshness, meaning, and pleasure of an experience. The intriguing hypothesis offered by Koo and her coauthors is that people can take active steps to elevate their moods by deliberately thinking about how an event is surprising.

An interesting twist is that people appear to be largely ignorant of this phenomenon. In the same paper, the researchers describe a separate set of individuals who were simply asked to imagine reflecting on how they met or might never have met their partners. These forecasters predicted that dwelling on how their relationship might not have been would dampen their spirits.

These findings lead us to a puzzle. Readers of both popular psychology and academic journals have undoubtedly taken notice of a growing literature on the benefits of gratitude – a body of work suggesting that “counting our blessings” (or reviewing the positive circumstances of our lives) makes us happierPrevious studies have shown that listing things for which we are thankful or writing a gratitude letter to a person who has made a difference produces increases in well-being and appears to neutralize negative emotions. Do Koo and colleagues’ research findings contradict the common wisdom and empirical support for the happiness-boosting power of expressing gratitude? I don’t believe they do. After all, how else do we strive to appreciate the good things in our lives – our health, our spouse, our garden, our 401k balances (if we’re lucky to still have them) – if not by implicitly imagining what life would be like without them? To be grateful for our eyesight, we imagine what it would feel like to be blind; to appreciate our next-door colleague, we contemplate what our work days would be like if he resigned. So, without even realizing it, people may already be quite proficient at the strategy of mentally subtracting positive events.

This research might stimulate some intriguing future studies. For example, might the process of mental subtraction backfire in people who are generally less happy, more pessimistic, and more inclined to ruminate? In such individuals, considering the counterfactual of how they may never have met their partners might trigger associated negative thoughts about their lack of deservingness or self-doubts or memories about other relationships that never came to be. Another fertile area to explore is whether the key to the mood-benefits of mental subtraction is surprise at the origin of a particular life situation (e.g., considering the many roads in life that may have prevented me from obtaining my job, and how truly unexpected it is that I wound up there) or whether the key is simple awareness and appreciation of the fact that all in life is transient and the future is unknown (e.g., considering that the job I love may be taken away).

The philosopher William James has been credited with being the father of modern psychology. He is less well known for making a rather revolutionary proposition: “My experience,” he wrote in 1890, “is what I agree to attend to.” Indeed, what we direct our attention to is our experience; it makes up our life. Where is your attention wandering now? To the almost empty 401k or to the steady paycheck, to your husband’s forgetfulness or to the many ways your life has been enriched since you met years ago? Instead of counting the ways that I love thee, Koo and colleagues suggest that I count the ways that I may have never had the chance.

Are you a scientist? Have you recently read a peer-reviewed paper that you want to write about? Then contact Mind Matters co-editor Gareth Cook, a Pulitzer prize-winning journalist at the Boston Globe, where he edits the Sunday Ideas section.