I wanted something avant-garde for the title, something wild and deliciously mysterious; yeah, that's what I came up with. In any case, on to the subject at hand.
I won't deny I had this thought put in my head from a friend who asked me a question just recently, but it's something I've thought about a lot, and maybe even written about before too, though not here.
Whether people ask this question frequently or not, I think they often wonder it about writers, or any "artist" who creates, and how much of the creation reflects the world they live in, the people they know, the lives they lived, as artists. Being something of an amateur writer, aspiring to someday be something of a professional and maybe even a decent writer, I may or may not have insight into all writers, but the majority, and myself included, fall under a few guidelines.
Because we aren't God, everything we create has a basis in our world. Whether it's a fantasy world in which everything we've built is simply what God made with as many differences as we can imagine, or whether it's characters pieced together from traits we've known, experienced, or sought to dream up. This is true for every writer, every painter, every musician, every filmmaker, every other kind of artist. We cannot create truly original material. God did that when he made the world and all that is in it and all that makes it work, things like the law of gravity. We can invent a world in which the law of gravity has no bearing, but that's only taking off of what God did—because as finite creatures, our minds can't exceed the boundaries of God's creation.
Don't get me wrong, that's not a bad thing, nor detrimental. The writers of the world have survived pretty well for a few thousand years on copycatting God's work, and they've even come up with some interesting stuff. But that's not really the main motive I've got for writing this.
To get a little bit closer to home, take novels written by writers with characters and places that sometimes are very obviously related to the world the writer grew up in. Not our world in general, since everything is directly related to it, but his own personal world: the relationships he had with bosses, family, friends, loved ones in general, etc. My own book, for example, deals with a lot of characters who were heavily inspired by people I know. Even events heavily inspired by things I've been through. For someone, aside from myself, to sift through what is "real" and what is "fictional" is going to be difficult. Even for family members and very close friends. When writers write, they use a portion of the brain most people don't use except for writing or creating. Everyone uses it at one time or another for one thing or another, but artists make using that creative portion into a living. You're reaching down an emotional well, searching for water, and no one, perhaps not even yourself, knows what's down there. (Here I go starting to sound like Inception.)
Everyone draws on their past, their desires, their friends, the people they come in contact with when they write. But the main reason you can never (or very, very rarely) take the fiction as being literal or completely metaphorical (most include partial metaphors) is that the one thing all good writers are good at is fictionalising events, making them good story material, whether they notice it or not. And so even if they were trying to write a complete truth, they couldn't after a point.
To take my book as an example, let's examine the general similarities between my world and the world of the characters. Most of the main characters can be traced in origin in one form or another to a person I know today. Someone I know pretty well, usually. However, what happens is that after a certain point, even when I don't realise it, the character traits and emotions of those people, and the events that govern their lives, become completely fictional. They may stay the people I know for a handful of pages, even a couple chapters. Then, no matter what similarities exist, they become what I call, "real with a very important twist: fictionalisation."
So even though the main characters are people I know, from myself to my best friends, to people I've known since I was only a little kid, even though that's all true, and on one surface level the characters can stay disturbingly close to their inspirations, all at once the events lose all correlation. I neither notice nor care what basis they had in reality; it becomes, at first without realising it, then without caring, a complete fictional "lie".
Maybe this is a long, complicated way to say something I could sum up by stating: no matter how much the characters may seem familiar in my, or any other book, the events of their lives take on a completely fictional reality, one which cannot be trusted to the real world.
It may be disturbing to see yourself in my book or any other book which the author has stolen your personality for a character, but you have to come to terms with the fact that the author is just a thief: all he really wanted was your personality, your character traits, and maybe a single event or two. After that, if you look for meaning in it, you won't find any. As much as we writers like to think that everything we write has some kind of deeper purpose, at least we talk that way anyhow, the fact of the matter is most of it is seat-of-the-pants, whatever pops into your head and sounds like it would make the story exciting. Sound careless? Maybe. Don't believe me? I don't know how else to explain it, and it may be disillusioning when it comes to some of the great writers of the world, and I won't say they didn't have a better grasp of what they were doing and the meaning behind it, but sometimes the moments we want most to take seriously, to find something in, are the moments which were thought of at two o'clock in the morning by a sleepy writer trying to finish his self-assigned chapter so he can go to bed.
Writers really aren't to be trusted. Every once in a while there will be some deep correlation betwixt reality and their created world, the lives in their life and the lives of their characters—but it's all the truth taken and twisted into some malevolent authorial purpose, often so distorted from reality that some of the very opposite things true in our world become false, and the falsehoods we know turn on head into truth.