I speak from my own experience, here. My experience involves public school, decades ago. I do not claim to have intimate enough knowledge of public school today to be certain that everything I say is still true, but from what I have seen in the news I suspect it is. Worse, I have a difficult time imagining how it could have changed.
In high school, among other various social classes, there are "nerds", and there are anti-nerd popular kids. The latter are often called "jocks" or "cheerleaders", or "preppies" (in the US sense of "preppies" being those who are sleek, polished social climbers, "prepping" for social success in later life), or any number of other terms that people find worthy of applying to the anti-nerd class. Of course, there are jocks and cheerleaders and preppies and whatever else who are not actually anti-nerd, but by far most are -- at least tacitly, or as a default avoidance strategy, or something like that. They generally can't help it; part of what got them there is at least subconscious recognition of the existence of a popularity-scale out-group that must, in some way, be disowned to become popular. Overcoming that recognition enough to defect from the party line is difficult; people seem built by nature for clique-building after all. It's a survival strategy, and high school is a savage world teaching the harsh lessons of survival of the most loyally aligned.
Of course, the aim of class alliances changes drastically outside of school. You're more likely to be shunned by the dominant class for political or religious beliefs than the true differentiating factor of the high school social classes of the nerds and anti-nerds. (Note I'm not saying those are the only true social classes in high school. I'm just saying something about the truth of these social classes.) That differentiating factor is whether or not you put enough time and energy into being popular.
Most popular kids spend most of their time worrying, on some level, about how to make sure they can be popular. This concerted, attentive effort poured into that single task, even if they do not realize the true nature of the overall task, is what makes it possible for them to be popular or, more precisely, how to not be nerds, or otherwise in an out-group. Most nerds spend most of their time worrying about things with more overtly objective criteria for success and less ancient stakes. They become experts in their own chosen fields, but those fields are not popularity, and if you are not an expert at popularity, roughly to the extent of your native ability, you are not popular at all unless by extraordinary luck.
After high school, the types of popularity criteria that some people pursued monomaniacally and (in such a small tidepool of society that was effectively their whole world) with great success become far less important. Those who adhere too unflinchingly to their popularity aims in high school often lose a lot of that popularity in the wider world, where the competition is both much more intense and much less important for happiness, in part because they cling so tightly to their high school popularity expertise. In fact, there is so much more variety in the world outside of high school that popularity can be had in many more ways. A nerd can strike it rich with an interesting technology and business idea, and find themselves surrounded by a crowd of fawning sycophants the likes of which high school prom monarchy can only dream. A popular kid from high school who doesn't learn how to grow into a larger world becomes an embittered failure.
Most popular kids in high school do learn how to grow into the larger world. Some learn it so well they continue to be fabulously powerful and popular, though they then find there are greater stakes and large, opposing "cliques" of popularity the likes of which would have been unthinkable in high school. The most absolute successes in the popularity game outside of high school must be so good at their work that they become malignant narcissists. Everyone welcome your new masters: the sociopathic politicians and their sociopathic accidental allies in big-business market dominating public corproations.
One might ask what happens to those who fail to adapt.
They become has-beens. This is, of course, a dreary, pathetic kind of life, deluded or self-destructive. Even so, this fate for the popular kids who never adapt is positively merciful compared to the fate of the worst-off of the nerd set. Some never recover, and die quite early. Some, even if they survive, die virgins, even if they really do want to have sex. The psychological scars of high school nerds are deep, and tend to plague them for the rest of their lives. If you meet a genuine high school nerd later in life, regardless of life-success level, and find that the person both seems arrogant and is not a true malignant narcissist, that person is almost certainly suffering from (occasionally crippling) impostor syndrome just under the skin.
Even that is not the full mercy granted to the has-beens. The world is always ready to welcome a has-been (or anyone else) who reforms, though perhaps a different part of the world than where the person lived before reforming. Being out of high school and no longer tied down by parental decisions, short extreme circumstances such as living in such abject poverty that taking a break from seeking food will mean your death, a person can always find a way to move to another place. One can reinvent oneself at any time, in the eyes of the outside world, perhaps by just seeking a different set of eyes as the audience. It just requires the will to do so, including the task of changing one's thinking -- a task many find nigh-impossible, though (seemingly paradoxically) that difficulty is purely a matter of choice as well for most people.
There is no such (relative) ease of correcting one's internal world. Psychological scars don't go away because you choose to change. The problem with psychological scars is that they actually change the world within which one lives. What we perceive is where we live, after all. How can one even determine how to change choices and actions for greater success in life if one's perception of the world for which one must change leads those choices astray?
In principle, one can change one's own behavior in an instant. Changing one's perceptions takes decades.
It is better, in terms of seeking success and happiness, to be a has-been than to be former high school nerd with persecution scars, because a has-been can become an is-now, in some way, in a couple short years. Solving the has-been problem requires only will. Solving the nerd-scar problem requires will, and also requires the development of whole new senses for observing the world. Being a has-been is attitude. Being a scarred high school nerd trying to navigate the world is who you are.