I think that, as writers, we all go through this worry. Our writing comes from very deep inside us. It's easy to fall into the trap of thinking that that makes it inherently narcissistic and self-serving. There's a conflict between the worlds in your head, which demand expression, their characters screaming to be let out, and the world outside, which seems to be full of grown-ups who do serious, dispassionate things like washing up, commuting and having jobs.
Even as I sit here typing this, by the way, I've got that little voice nagging me if I really believe anyone else has such a pathetic, selfish problem.
I normally try to avoid obscenity on this blog, but fuck that little voice with a big, sharp, splintery stick (because, yes, Richard, the best possible way to emphasise this topic is with a mental image that no-one wanted to think about...).
I talked briefly in the opener to this series about personal or psychological freedom to write - the freedom you give yourself. What I meant by that is freedom from that little voice. This might be the hardest of the three freedoms I identified to achieve, because it's your own attitude you're going to have to fix. You're going to have to teach yourself that you have a right to write, a right to express yourself through your work,to write about whatever you want to write about and not let the little douting voice put you off.
(Sidebar: There are all sorts of pathological psychological conditions which can produce severe versions of this effect - depression, anxiety, low self-esteem and so on. If you find yourself constantly experiencing this kind of doubt, particularly if it's across everything else you do as well, get professional help. I'm in the process of counselling for exactly these kind of problems at the moment. Your problems are not insignificant - and the fact that you may think they aren't is usually one of the strongest signs that they are.)
I can't offer counselling - I have absolutely no training and very limited experience in that area. What I can offer, and I hope it will help, is the reason why you should write even if you think no-one should care. In fact, I can go one better - I can give you a reason why you absolutely should write the stuff you want to write, but that you think no-one will care about. Hopefully this will keep you going (and me, too - I still want to write that video-games-and-literature post).
Let me start from this: there have been lots of great writers. Whether you point to Shakespeare, Keats, Dickens, or any of the greats of non-English literature (about whom, being an arrogant anglophone, I have basically no knowledge at all...), you have to ask yourself what you've got to offer that they haven't.
Hint: the answer isn't 'nothing'.
What you have to offer is the stuff that's most unique to you. Trite as it sounds, there's never been a writer quite like you before. By way of example, my first novel was a narrative deconstruction of the aesthetic theory of Lady Gaga, told through the story of a man posing as a woman to stalk a pop star via the internet. I doubt anyone else ever could have written it (or would have wanted to - and just so we're clear, it's not autobiographical :-P ). I still have difficulty convincing myself anyone would want to read the thing, but it's what I have to offer (someday, when I get round to giving it the rewrite and polish that any first novel needs).
Another example from my own experience; I'm taking a break from The Second Realm at the moment and working on a short story about a character dealing with more or less the same psychological issues I am. Partly as a coping mechanism, but mainly because the great inspirer in the sky reached down, handed me the story and said 'Write this down, it's yours'. Needless to say, despite all the aliens and stuff (I'm not going to start writing boring stuff just because I'm being serious, now am I?), it's a pretty intense, personal experience, and publishing it will be worse.
There's a wonderful quote from Patrick Rothfuss' 'The Name of the Wind' which (though actually about something slightly different) I feel sums up the feeling perfectly:
"Go out in the early days of winter, after the first cold snap of the season. Find a pool of water with a sheet of ice across the top, still fresh and new and clear as glass. Near the shore the ice will hold you. Slide out farther. Farther. Eventually, you'll find the place where the surface just barely bears your weight. There you will feel what I felt. The ice splinters under your feet. Look down and you can see the white cracks darting through the ice like mad, elaborate spiderwebs. It is perfectly silent, but you can feel the sudden sharp vibrations through the bottoms of your feet."Possible scientific inaccuracies aside, I think that's a beautiful metaphor for the creative process. Go out to the furthest place you can stand, stay there well past the point of safety, and see what happens. It might not be best for your health and well-being, but it's only when you're right out there that you stand to do something special.
All the danger and the fear come from the exposure - the stripping bare of your deepest and most passionate parts (no, not those parts. Put that away, for Heaven's sake). And because brains are trixy things, yours is going to find any excuse to avoid that, to avoid the fear, the chance of humiliation, the mockery.
So it convinces you that the humiliation is inevitable. That the things you want to write about don't matter and will be regarded as silly or frivolous by the world at large. That when people have a positive word for you, they're just being kind, not honest. That when they don't, it's not because they're busy, or just as wrapped up in their own problems as you (how could they be, when your problems are so unusual and pathetic?), but because they revile you so much they can't even bear to be polite.
But the things that are most personal to you aren't just the things that are most important to you. They're the things that are most important about you as well, and you have a right to tell the world about them (just so we're clear, that's not the same as the right to make a public nuisance of yourself, pestering people in the street to listen to you ;) ). The world has a right to know, and I guarantee you someone out there is interested enough to listen.