Imagine that you have a flight at 8:00 in the morning. Which would be worse, arriving at the gate, breathless, at 8:02, just after they’ve closed the door, or at 10:00, thanks to a couple unplanned delays in your morning. Obviously, the first scenario would cause far more misery, but why? Either way you’re stuck at the airport until the next flight, eating the same bad, overpriced food, missing whatever you were supposed to do after your planned arrival, whether that’s meetings or a stroll on the beach.

The difference between the two scenarios is the intensity of the regret you would feel—a great amount in the former and a lot less in the latter. As it turns out our happiness frequently depends not on where we are at the moment, but how easily we perceive we might be elsewhere, or in another, better situation. With the missed flight, you’re in the airport either way, but when it’s a close call, you can think of a dozen little things that would have changed the situation, and each one brings a pang of regret. So, the closer we are to this other possibility, what we refer to as counterfactual, the unhappier we become.

While there are plenty of things in life that cause disappointment and aggravation, consider the case of Costis Mitsotakis, a resident of Sodeto, Spain, who was the only person in this 70 household village who did not receive a share of the $950 million lottery payoff. The story is this: every year the homemaker’s association of Sodeto sells tickets to all the residents, and in 2011, their number won first prize (shared with 1,800 other winning tickets, but still an immense payoff for a tiny, economically depressed town). When the townspeople heard the news, they ran outside, and were congratulated over a megaphone by their jubilant mayor. But soon it was discovered that one resident hadn’t bought a ticket—Mr. Mitsotakis, who had moved to Sodeto for a woman with whom things did not work out, was overlooked when the homemakers made their yearly rounds.

In this case, the counterfactual looms incredibly and painfully large. If only they hadn’t skipped his house or he had run into them at some point—the smallest earning from the lottery in the village was $130,000, and some won more than half a million dollars. If that wasn’t bad enough, the reminders of this alternative outcome will last for the rest of his life, or at least as long as he remains in Sodeto. Mr. Mitsotakis will be continually reminded of the tiny difference in events between his life now and what it would have him. If I were him, maybe I would simply move. This would probably decrease his happiness in the short term, but in the long run I think his life would be much better, and much less regretful.

So, next time you miss a flight, are first in line after tickets sell out, or get stuck in traffic after trying out an alternative route home, just remember, your situation may be frustrating, but it’s not like you lost half a million dollars and it is not as if you will keep on remembering this for the rest of your life.