So here they are:
1. There is hope. I was a bright child. I was rejected to greater and lesser degrees by my family, my schoolmates and my teachers. Being clever doesn't win you many friends. Sometimes none at all. I grew up in a working-class city in the North of England. The people around me were poor, ill-educated and, almost without exception, ignorant. Most of them were also very stupid. Yet I found a way through. I was certainly luckier than many - my mother was bright and supportive, and I got a free, university-level education. I left the place I grew up in and went in search of better places. Eventually I found them. It's a very big world and there are many, many niches in it. Keep looking and you may find yours. It helps the search if you move to a major city.
2. Other bright people can sustain you, even if you never meet them. I'm not just talking about the Internet, here, although it's an obvious place to look for like-minded people. I didn't have the Internet when I grew up, but I had books. Read widely and read good stuff (on- and off-line). You will find that many of the people who became great writers also went through what we did. One of the best moments in my reading life was when I discovered J.D. Sallinger. In his short stories in particular, I often got that heart-stopping moment of recognition when I realised that this man knew my pain. Maybe Sallinger will do it for you too. Most likely it will be someone else. Just one word of advice - especially about the Internet. While it is easy to find fellow sufferers, and wallowing in misery together can be a relief for a while, in the end, you will get more of a lift out of positive, strong people. However bright you are, you're only human and you have the same psychology as we all do. Don't get locked in a downward spiral of self-pity with someone else. You'd both be better off on your own.
3. Work can help. Clever people tend to be good at certain things. They make good scientists, engineers, writers, and so on. Even in less intellectually challenging jobs - as administrators, planners, managers, etc. - they tend to shine. They might not get the promotions, they might not get the big bucks - for that you also need social skills which cleverness does not guarantee - but they do their jobs so well that they earn the respect of their peers. Respect isn't love, it isn't necessarily acceptance, it isn't even kindness, but it's something and it is not to be sniffed at. Respect from others helps you respect yourself - and self-respect helps in many different ways.
4. Don't worry about the meaning of life. There is none. Bright people are their own worst enemy when it comes to seeing through the crap. Sooner or later, you will conclude that there is no god, there is no deep meaning to the Universe, you have no destiny, and, in fact, there is no point to anything at all. That's fine, but you shouldn't let it worry you.
'Purpose', 'meaning', 'point' and so on are ideas that people come up with , they are not things we find in nature. The 'purpose' of the rain might be to make the crops grow, but we all know that is just a semantic confusion. The physical word doesn't have purposes, only people do. In the long term - the next ten billion years, say - nothing about humanity matters at all, not least your own little wants and needs, your hopes and ambitions, your loves and hates. However, we don't live in the long term. We don't live ten billion years. We live tiny, proscribed little lives. We flicker into self-awareness and are gone in a moment.
Yet, to us, in that moment, our own feelings, desires, and purposes are everything to us. And that is important - by definition. We are the creatures who give meaning to the world. We are the ones who provide purpose to the Universe. We are the ones that imbue existence with value. While we live, while we think and feel, we bring this into reality. You and I create the meaning of the Universe, quite literally. It is ours.
So don't feel shy about the purpose of your life. If you want an iPod, if you love the boy or girl next-door, if you have a craving for a swim, or to work in outer space, each of these is, in a very real sense, the highest purpose in the world - because it's yours, right now, and that, literally, is what matters in this otherwise indifferent Universe.
5. Find out who you are and accept it. The biggest advantage of being clever isn't that you can make money, or design cool stuff, or argue everyone else under the table, it is this: you can understand yourself and the people around you. If you don't understand yourself, you will always be doing stupid things that don't make you happy. If you don't understand other people you cannot love them and you will always be doing stupid things that don't make them happy either. It took me a couple of decades of very hard work to get a deep and thorough understanding of myself and to accept who I am, warts and all. It was the most difficult intellectual challenge I have ever faced - the most difficult emotional challenge too - but it was worth it. Well worth it. It requires strict intellectual rigour. It requires ruthless, painful honesty. It may require you to throw out many myths about yourself and your world that you cherish and hide behind. Don't waste that glorious brain of yours. It's caused you a lot of pain and heartache, set you apart, driven people away. Now, for once, get some good out of it. Use it for something that will really benefit you and everyone around you.
6. Never forget what you are. You are a human being. You evolved from ape-like creatures, who evolved from other creatures. As clever as you are, you are still an animal. You have the physiology of an animal and, importantly, the psychology of an animal. The kind of animal you are has psychological needs for the company and intimacy of its fellow animals. You can't fight your own psychology so try not to. Being cut off from the society of people is what is making you feel bad. Going along with that and cutting yourself off even more will only make you feel worse. The smart thing to do is to understand your animal nature and to start organising your life so that its needs are satisfied. I'm not talking about sex and eating and sleep and all those other 'drives' - although they are important - I'm talking about social interactions, social approval, gossiping, sharing rituals, and finding friends. Right now, those things may seem a million miles away from where you are - but that's what all the points above are about, getting yourself into a societal niche where you fit, finding people who like having you around, ditching false notions that will add to your troubles, and becoming so comfortable inside your own skin that you can face the world on equal terms and get what you need from it.
It will always be the case that you are in a minority. Always. But you don't need six billion people to accept you. You can make a great life with just a handful of close friends and family who see the way you are as a desirable quality, not a freakish aberration.