The study's co-author, Regina Miranda of Hunter College, explains to PsyPost that previous research focused on "understanding and changing negative cognitions (including cognitions about the future)," but their study aimed to uncover why even positive fantasies about the future can leave us bumming. It's all in a word: rumination—basically, thinking about something over and over and over.

How can thinking about something be bad? After all, you were only looking at hiking gear for Machu Picchu. That's harmless, right? According to the study, yes and no. Miranda and her colleagues write that rumination can take two forms: reflection, referring to goal-oriented reflection that could lead to real solutions; and brooding, which involves just dwelling on a bad mood.

While we generally consider fantasizing about the future to be in that former camp, the study, which surveyed 261 undergraduate students about just this thing, found that that's not necessarily the case. If you do it once in a blue moon, you're probably fine. However, "when people indulge in positive fantasies about the future more consistently, or when people's fantasies increase," they start brooding. Stewing in that bad mood can make it more difficult to be optimistic about the future, and you brood even more. A real catch-22.

Ok, so even if you do research flight deals to Peru on a regular basis, why would that necessarily lead to brooding? Miranda and her colleagues laid out two ways this could happen. First, if you fantasize about traveling to South America, but you don't actively commit to things like saving money, securing the days off from work, or getting your body hiking-ready, this failure to reach your goal could lead to depressive symptoms.

Or, in the more abstract, maybe you never actually believed that a trip to Peru was possible in the first place. Now, that's a bummer. Miranda acknowledges that more research needs to be done, however, and even notes that a third variable may be involved.