Social anxiety can hit anyone at any point in life but often times it attacks us early on in our teens and continues through adulthood. While this isn't necessarily a "goth" problem, it does account for why some "goths" are so reclusive. For those that don't have the issue it's difficult to understand how god-damned unpleasant it is for the person who has it. It's NOT a problem we asked for and often times isn't even technically our own fault but we get shit for having the issue anyway.
Too often people will call those with social anxiety recluses, fools, lazy, too introverted, unwilling to participate in life. All those things are terribly false and show how the ignorant just don't fucking know a damn thing about what they're talking about. For starters, lets explain what social anxiety is:
Social anxiety is an abnormal, often intense fear of talking with, being around, or seeing other people or a group of people (often times the stress will be so immense a person goes into a state of panic thus resulting in an anxiety attack or panic attack). It's also a pain in the ass when it comes to trying to find work and going to interviews (you're so damn nervous you talk a thousand miles per minute, fumble at times with your words, nearly run into things on your way out (or in) the door and thus have left an odd impression on the employer). It's a painful problem that causes numerous missed opportunities. It kills friendships and relationships because you're fearful of going out in public (real friends may stick by you though, maybe). In the worst case scenarios it can be deadly because at times you can be so freaked out by other human beings' thoughts, perceived or delusion, that you avoid going to the doctor for an ailment.
What starts the social anxiety usually has much to do with our early interactions during childhood. If a child is repeatedly rejected, ridiculed, or neglected by his/her peers or parents even, they eventually can come to develop this anxiety. It's seen more often in girls (because girls can be such bitches to other girls; i know firsthand) but boys are not immune to the condition. We come to fear, through obvious habit, being judged and thus socially rejected for so many years that our brains don't want to let us be involved with other humans. It's plain to see why this is more common amongst females as females are the more social of the genders to begin with (and this is true in many animal species as well) and the females rely heavily on the bonds with other females to feel comfortable and secure. We see this in many animal species as well as our own, it is the females that work together to get things done, so the need for bonding is very strong. Being human, we learn from observation and once the observation is made clear that we are not wanted in a group (or many) our brains decide to build barriers to protect us from the harms that this group (or groups) may cause. By the teen years, if the rejection and cruelty does not let up, we start to distance ourselves from the problems and some of us do such a good job at distancing ourselves we don't feel right in any group setting. By adulthood, without psychological therapy (pills aren't much use), we become loners and have trouble getting much of anything done that involves a social situation including getting a job. At this point we feel we are so inadequate socially (and personally) that no employer will have us or that we will fail once we get into the position.
Some will say, "oh it's just low self-esteem, it's not that bad". Those people don't know what the fuck they're talking about. It's a hell of a lot more than that and a hell of a lot harder to overcome. Some have better days, where they're able to at least pick up the phone to call for a pizza. Then there are bad days, where you fear going to the store because you'll have to talk to the cashier for a brief 30 seconds. For a few people social anxiety is a chemical imbalance, for others it's been a lifetime built problem that only a psychologist can help you through. Some people have just a mild case of the issue and can talk themselves into calmness during social situations while others have it so bad they almost (almost) qualify for social security disability because they're unable to leave their homes without getting panic attacks.
All this shit is caused because we encounter so many assholes when we're kids. And it seems with every new generation of demon spawn, those little demons get more and more cruel and find new and unique ways of tormenting their less attractive (or less socially accepted for some reason) peers. So to all those dipshits that think they understand social anxiety and call it a "minor" problem, FUCK YOU, the majority of you assholes probably helped cause the problem of social anxiety for someone out there.