As Hanne Blank detailed in her excellent book Virgin: The Untouched History one of the difficulties in defining virginity, or saying who is and is not a virgin, is that there has never been a single definition of what exactly makes someone a virgin.
Historically the term has been used to describe some state of being chaste, pure of thought and deed, which usually meant not having had sex. Of course definitions of sex themselves are slippery. Are you a virgin if you masturbate? Are you a virgin if you kiss? If having had vaginal intercourse is the marker of losing ones virginity, then what about people whose sex lives never involve vaginal intercourse because they never involve a vagina? Do they stay virgins forever?
Today there seem to be many different kinds of virgins. In popular culture and even sometimes in the scientific literature you will hear about "technical virgins," "vaginal virgins," and "born again virgins." Each of these terms may mean something different depending on who is using it and why. Which means probably the best approach to talking about virginity and virgins is to start by breaking down what the person talking, or writing, means.
There are still many people, many communities and cultures, that connect virginity to a woman's hymen. The hymen is a thin membrane that partially covers the vaginal opening inside the body. But contrary to myth and legend, it isn't a solid structure that is 'broken' or 'popped' during intercourse (if you're interested in learning more about this check out the international effort to rename the hymen the "vaginal corona"). Using the hymen as proof of virginity makes no sense anatomically (since hymens aren't solid and are often torn before a woman begins to engage in sexual activities), it also makes no sense conceptually since it would mean that virginity only applies to those people with vaginas and hymens.
One way to break down virgin terminology is to clarify first whether virginity refers to something physical and behavioral, or whether it refers to an emotional or psychological state of being. Probably the most common understanding of what it means to be a virgin is that you haven't engaged in sexual activities of some kind. The old idea that to be virginal you have to not have sexual thoughts is less common today. So if being a virgin means not having sex, then the definition of virginity depends on what kinds of sex you believe count as sex. Since there's no general agreement on this question either, it seems reasonable to say that people can decide for themselves if the term virgin is one that fits, one that feels good, and one they want to use.
This is the approach most sex educators who provide comprehensive sex education take to defining virginity. Virginity isn't a medical condition. It is a label and an identity, and one that gets used to hurt people (usually women) physically and emotionally. So any question about who is or isn't a virgin should really open a conversation about what exactly the people who are making claims are talking about.
Back to the myth and legend, people may claim that no longer being a virgin means you are more mature, wiser, more interesting, or even better at sex. But having had sex doesn't actually make you any of those things. You can have hundreds of sexual partners and learn nothing about how to have sex (or how to be a good person). And you can have a relationship that involves little or no sexual touching and develop empathy, knowledge, and even wisdom.
Moving from being a virgin to no longer being a virgin isn't like passing your driver's test. There isn't a standardized set of skills and knowledge you need to demonstrate in order to say you are no longer a virgin. And it may be worth remembering that having a driver's license doesn't guarantee that you are a good, or safe, driver.