In August 1987, in the midst of one of the darkest periods in English soccer history, a countercultural movement sprung into existence in the stadium of the Manchester City Football Club when a man named Frank Newton brought a five-foot inflatable banana to a game for a laugh. Laughs being rare in the stands at that time, other fans embraced the idea of inflatable bananas and a trend bloomed. Vendors started selling them. Newton himself soon switched to a six-foot inflatable crocodile, according to a definitive account at the Manchester City fan newsletter MCIVTA. Other fans hoisted inflatable sharks, airplanes, and wading pools.

This craze was exactly the sort of thing one might expect of Manchester City fans, lovable losers who had invented their own methods of coping with a team notorious for weird failure. The team had bounced around between leagues and hadn’t won an English championship since 1968, but the fans’ sense of dark humor made them resilient and loyal.

In 2012, four years after a private equity firm owned by a billionaire member of the royal family of Abu Dhabi bought MCFC, the team won a Premier League title for the first time since 1968. The team won it again in 2014. And while there was much joy at the end of such a long title-drought, there was also some head shaking. Fans had gone from being famously persistent losers, supporters of everyone’s second-favorite team, to being front-runners, supporters of one of the world’s most valuable and successful sports teams. “Success has come but I think many older fans feel strangely conflicted by now being one of the teams-to-beat,” ESPN FC Managing Editor Steve Busfield told me a few years ago, when I was conducting research for my book about sports fan psychology. “City fans used to be joyful in their misery.”

Which brings me to the resurgent New York Mets, and their fans. When Frank Newton brought his inflatable banana to Manchester, the Mets were the defending World Series champions. They haven’t won it since, but now, the franchise commonly tagged #LOLMets, finds itself one of the two most successful teams in baseball. They’re behind in the World Series this year as it moves to New York for Game 3 on Friday; but win or lose, they have a talented roster and great young pitchers. They’re already the National League champions, and there’s no real reason to think this year’s success will be a one-off event. Psychologically, does it mean anything for fans accustomed to defining themselves as “not the Yankees” to suddenly start winning? Say the Mets winning streak continues for another few years and winning’s not a miracle anymore: does the experience of being a fan change?

Mets fans resemble pre-2012 Manchester City fans. (Disinterested armchair theorist disclosure: I’m neither.) They’re eminently lovable to those of us who don’t love the Mets. It’s an affiliation that allows one to be a sports fan, but not really one of those sports fans. For example, think about how different it would be on the Daily Show if Jon Stewart had always talked about his Yankees fandom. To call yourself a Mets fan is an obvious demonstration of personal loyalty: if you’re wearing a Mets hat, you’re obviously not a fickle front-runner. You can—or could—trust a Mets fan.

People are motivated to be sports fans for a variety of reasons, according to Murray State psychologist (and Kansas City Royals fan) Daniel Wann. One reason is that winning produces an increase in the fans’ self-esteem . There are a lot of very interesting ways to explain why this happens; for now, let’s just assume it does. So Mets fans, whether they’ve suffered every insult since 1987 or joined the bandwagon this year, enjoyed a nice sense of well being following the team’s defeat of the Cubs. If the team comes back to win the World Series, fans will enjoy another round.

There are also theories of pride, such as the one advanced by psychologists Lisa Williams and David DeSteno, that suggest that pride is just externally validated self-esteem, which is to say, when you know you’ve done a good job and you know that others know you’ve done a good job, you become more prideful. Williams and DeSteno suggest that this explains the evolutionary origins of pride: it’s there to help you persist in dull tasks with delayed payoffs. Winning on national television means that Mets fans, again, regardless of the duration of their fandom, should also feel pride.

For bandwagon fans, who’ve joined up this year, that’s essentially the extent of the payoff. They’ll experience, in the moment, self-esteem, pride, happiness, entertainment, fun -- and no emotional or psychological complications. This is a great argument for being a bandwagon fan, and also one of the reasons we’re so frustrated by them—our keen sensitivity to freeriders makes us skeptical of people who are receiving communal benefits without having put in the suffering.

Why would anyone stick with a losing team, then? The case of the Manchester City fans and their bananas suggests one way of thinking about it. Sports fandom is one of the more accessible, more obvious, more fixed sources of identity out there in the world. Win or lose, the existence of the relationship props you up. A sports team and its fanbase are an anchor point in an inconstant universe, fulfilling a need for belonging that, some researchers argue, is as fundamental a motivator to us as hunger.

Winning can, beyond the fans’ control or even desire, reshape the identity of the group the devotees belong to. Older Manchester City fans delighted, of course, in the championships, but also felt some mixed-up sense of loss about the new version of the club—and its fans—that wasn’t quite like the old one they’d fixed their personal star to. Red Sox fans after the team won the World Series in 2004 and 2007 suddenly became, to everyone else, no different than the overconfident supporters of the archrival Yankees. Golden State Warriors fans, long among the most loyal and most likable in the NBA, have reacted with endearing astonishment to find that, after the team won its first title since 1975 earlier this year, lots of people suddenly intensely dislike them. This identity crisis has a parallel, I believe, in the emotions of empty-nester parents dropping a child off at college. We’ve come such a long way and succeeded! But … we’re not the parents of a dependent anymore.

Identities change, of course. But as one sports fan sociologist pointed out to me, there’s a reason that the perpetually losing football team leaving Cleveland for Baltimore in 1996 was treated by many fans as the equivalent of a death in the family. The identities we vest in sports teams matter, and it’s hard on fans when that source of identity is taken from them.

People dismiss sports fans and the emotions they inspire, but an understanding of how people behave, and the various ways with which they connect—and multidisciplinary lines of evidence from psychology, neuroscience, endocrinology, and sociology—suggest there’s no affectation and no theft of undeserved glory here. The team wins; the euphoria is totally real. This is your brain reveling in what it senses and processes as its own monumental accomplishment.

But with persistent success the euphoria fades, and fans confront the next question: who am I now?

You wouldn’t trade the success, just as you wouldn’t want your college kid returning to diapers and spitting on you. But sometimes even the successful parent would just like to be—for a few minutes—the person who woke up three times a night to soothe a crying baby, who didn’t know it would all turn out okay but persisted anyway in the hope that someday it might. Sometimes the successful sports fan, the winner, pulls the inflatable banana out of the closet and thinks about it, and the person who carried it, and what it meant, and doesn’t mean anymore.