When a good thing comes along, humans have a frustrating tendency to overplay the effect it will have over the long term. This, we tell ourselves, this will be what finally makes us happier: getting married, buying a house, going on a dream vacation, landing a coveted promotion.

And for a little while, it probably will. But nothing lasts forever, happiness included. Eventually, everyone goes back to baseline. One study found that the initial excitement of marriage tends to wear off after two years; another suggests that the honeymoon period in a new job lasts a year, on average. Even smaller pleasures — a slice of cake, a new hobby, a day off work, a different hairstyle — may feel more fleeting than we’d like. And once the magic wears off, we’re left to pursue the next thing for the same result. Psychologists refer to this phenomenon as “hedonic adaptation,” or, sometimes, the “hedonic treadmill.” It’s an apt image for what’s going on in our brains: always running toward sustained happiness, never quite reaching it, forever chasing the reward that remains fixed in the distance.

Researchers believe hedonic adaptation is a protective mechanism, preventing external stimuli from having too great an impact on our internal state — kind of like the happiness equivalent of sweating to keep cool. Some have even called it a “psychological immune system,” since adaptation is how we bounce back from whatever life throws at us. But it’s often detrimental instead, sometimes to the point of making us question the choices we’ve made in the pursuit of happiness: Maybe I married the wrong person. Perhaps this isn’t the right career for me. I’ll try a different flavor next time. And self-doubt aside, wouldn’t it be nice to slow down the treadmill at those moments of joy and linger in them a little longer?

Research suggests that it’s possible — at least, up to a point. In 2005, psychologists Ken Sheldon, Sonja Lyubomirsky, and David Schkade authored a paper breaking down the factors that influence our happiness. Around 50 percent is based on fixed traits like personality and genetics, they wrote, while another 10 percent is influenced by circumstances, leaving 40 percent within our control, malleable with what the authors called “intentional activity.”

Together with Lyubomirsky, a psychology professor at the University of California, Riverside, Sheldon developed the hedonic adaptation prevention (HAP) model, a strategy for slowing down the deterioration of happiness that follows the boost from exciting life events. The key to holding on to happiness, he says, is twofold: appreciation and variety.

Adaptation can make us question the choices we’ve made in the pursuit of happiness: Maybe I married the wrong person. Perhaps this isn’t the right career for me. I’ll try a different flavor next time.

Appreciation — which the pair described in a 2012 paper as “the psychological opposite of adaptation” — means “intentionally savoring the state of affairs, or intentionally cultivating gratitude,” explains Sheldon, a psychology professor at the University of Missouri. By paying more deliberate attention to the root causes of your happiness in a given moment, you give that happiness more staying power. Next time you’re on a trip, for example, take a step back to relish the circumstances that got you there: “‘I love doing all this traveling with my wife. I’m grateful to have such a great marriage!’ [Thoughts like] these help limit the development of envy and desire for more than what you already have,” he says.

But appreciation is easy when you’re in the thick of the good. It’s when negative thoughts start to creep in that it becomes more difficult and more important. Try to regularly remind yourself of why you should still be thankful, even when it feels like the good no longer outweighs the bad to the same extent. Tell yourself things like: “I’m so glad to have that extra money that came with my promotion, even if it means I have to work much longer hours.” Or: “It’s so nice to be free from living under a nosy landlord, even though my house keeps needing expensive maintenance.”

In another way, variety might also be considered the opposite of adaptation. By having “many memorable, positive events day to day,” Sheldon says, you can prevent your brain from getting too used to any single one too quickly. Everyone has go-to experiences to perk themselves up — a favorite meal or activity or spot to go out, for instance — but try mixing up your sources of enjoyment. And when you’re on the other side of a big life change, focus on ways to vary the small changes that stem from it: Invite a co-worker to lunch at your new job. Make your home feel fresh again by periodically rearranging the space. Explore an area of your neighborhood you haven’t spent much time in. Use date nights with your new spouse to try different restaurants.

“The more varied [your experiences] are, the more memorable they are, and the more they factor into well-being judgments,” Sheldon says.

But cultivating happiness isn’t a one-size-fits-all affair. If appreciation and variety don’t work for you, Jordi Quoidbach, a psychology professor at the University Pompeu Fabra in Spain has identified another strategy in his research: occasional abstinence from something that makes you happy. Too much of a good thing, Quoidbach has found, can have a dulling effect. If you keep chocolate on hand all the time, it doesn’t really feel like a treat anymore. If you and your spouse both work from home, you may see too much of each other and never have that “excited to see you again” feeling. One of Quoidbach’s studies found that just feeling well-traveled, regardless of actual experience, can make people less interested in spending time at a given tourist destination. Spacing out your pleasures can make each one that much more potent.

Other research has turned up additional tricks for prolonging a specific happiness. Jeff Galak, an associate professor of marketing at Carnegie Mellon University, has found that ascribing sentimental value to an experience can be a powerful antidote to hedonic adaptation. Sentiment, he argues, remains stable over time, absolving things of the need to be new in order to bring joy. Researchers at the University of California, Irvine, also found that telling others about a positive experience can extend the happiness you derive from it.

Each of these tools, in its own way, is trying to delay the point where a situation begins to feel ordinary. And it helps to remember that ordinary is not the opposite of new — there’s joy to be found in an experience even after its novelty wears off. Whether it’s ice cream, an exciting trip, or your marriage, the key to slowing down the hedonic treadmill is to regularly remind yourself how good you have it.