Jack Torrance: Wendy, let me explain something to you. Whenever you come in here and interrupt me, you're breaking my concentration. You're distracting me. And it will then take me time to get back to where I was. You understand?
Wendy Torrance : Yeah.
Jack Torrance : Now, we're going to make a new rule. When you come in here and you hear me typing
Jack Torrance : or whether you DON'T hear me typing, or whatever the FUCK you hear me doing; when I'm in here, it means that I am working, THAT means don't come in. Now, do you think you can handle that?
Wendy Torrance : Yeah.
Jack Torrance : Good. Now why don't you start right now and get the fuck out of here? Hm?
-From Stanley Kubrick's The Shining (1980)
Concentration. That's the trick isn't it. Most of us writers have, at some point or other, imagined the perfect writing environment: a secluded spot with all our favorite books, and writing materials, and no one to bother us for hours at a time. Not many of us, however, here in the fucking real world, have much time of this sort (I've heard a rumor it doesn't even exist!); unless, of course, you are able to support yourself financially with your writing, or happen to have a trust fund or inheritance or a rich husband/wife (or you happen to stumble upon a Van Gogh in your basement or some pirate gold), you probably have a job that takes up most of your time. And you might have a husband/wife who is as equally bereft of financial security as you are, and perhaps kids, and perhaps a lot of other things going on in your life. All these things make it very difficult for us writers to do what we really want to do and do it well; we want to write, but how can we with all these distractions?
But, honestly, can you really only write in total secluded silence? Don't you play music or have the television on low in the background? I've found that a few distractions are not as bad as you might think. You can write even with things going on around you and someone knocking on your door every few minutes with questions and other such annoying things. I believe it is a myth that one can only produce quality writing in a vacuum of total concentration; some distractions may even be good. I believe us writers have to learn how to write in short bursts and in multiple sections without losing the overall focus of our work. This is the same practice we have to learn with our reading; to be able to snatch a couple of pages here and there at breaks and in between the everyday-mundane-action of our lives.
The problem is, of course, in maintaining focus and tone in the piece you are working on; and it's not easy. Every individual is going to have to find what works for them, but for me the trick is to keep careful notes of what you are trying to write; about character motivations and possible plot events (which will likely change as you write if you are an organic writer like I am). It's not a perfect system and re-writes are inevitable, but it allows me to produce even though I have very little scheduled writing time by myself. It's a tough skill to learn, to be able to plug-in in an instant and pound out the next couple hundred words on your current project, but it is possible. If you are a writer, it is important (absolutely imperative) to find a way to write no matter what.
This is not to say that having specific times set aside where you can close the door and write for a couple of hours without being bothered are not invaluable; they are. Stephen King writes for 6-8 hours undisturbed every day, but he's one of those I mentioned earlier who writes professionally (and makes a boat-load of cash doing it!), but he got there by writing on his lunch breaks and after work, publishing short stories in small magazines and working his way up from there. Probably none of us can expect to ever reach the commercial success of King; he is, after all, perhaps the single most successful novelist of our time (of all time?), but we can write goddammit, and we can find fullfillment in the fact that we are expressing ourselves; this is important in a world where 90% of its people are emotionally-stunted lumps hypnotized by television and advertising that will contribute very little to the world before their eventual deaths. All I'm saying is that at least we have something, even if you're never published and only your family reads your work - you still got a piece of yourself out there. That is why (well, it's one of the reasons anyway) we find time to write, even though the mundane outer-world keeps pulling us back.
Which brings me to the quote above from Kubrick's movie version of The Shining. I think Stephen King would agree with me on a few of my points; he understands that some of the best writing is done in a state of concentration, becoming completely immersed in your work, but he also understands that some of the best writing is done under less, shall we say, desirable circumstances. It's about writing, no matter how you do it, as long as you do it. No matter how much undisturbed writing time Jack Torrance had (the Overlook Hotel is strikingly similar to the writing retreat King describes in On Writing - hmm...) he just couldn't get all those voices from the hotel out of his head; he just couldn't keep from going stir-crazy and chasing his family around all those creepy hallways with an ax. There's a lesson here...
BTW - The Shining (Stanley Kubrick, 1980) is a very good horror movie. Most have probably seen it; if you haven't, you probably should (and I have so much to teach you...)