Roland Barthes wrote The Death of the Author. The idea behind this, is that once something is written, it no longer is the author's thoughts or feelings...when reading you cannot factor the author in because it's not him/her thinking/feeling it, it is purely the character. My thoughts on this is that the author removes him/herself from the story so that when you (the reader) reads it, you're not thinking "Did this actually happen to the author?" "Is the writer really this angry?"...It is the writer's job to be able to claim fiction and remove themselves far enough away from their work that they can talk comfortably about it. So that when the love interest dies, they don't break down. After all, this work is fiction. NONE OF IT IS TRUE.
To be completely honest, this is all horse shit. While fiction writers aren't writing a memoir, they still put themselves into their work. For example (and the example I used in my lit theory and criticism class): I wrote a novel about a girl who keeps secrets. In one chapter, you find out she has a brother who abandoned her and her sisters. I took the piece, read it to the class, asked if anyone had ever read this before (claiming it to be written by someone else). No one (save a friend) had read the piece. I asked how things changed if I said I wrote it. The nonfiction portion: I have a brother (half brother) somewhere in the world. I loved him as a child, he left us. Without him, this portion of my character would not exist. However, I am not my character, and she is not me.
Moral of this blog is that all of my characters have traces of me in them (people who know me well enough constantly call me out on this). Some have anger problems, some have mental problems, some fall in love too easily....But the better part of writing is that you can make these people do whatever you want: they can commit murder, they can jump off a roof and be fine, they can fuck the entire soccer team. They can have political views that differ from your own, they can experience things you'll never be able to.
But at the same time, this person you created, you end up loving because well, they're a part of you. You've just invested a day/a week/any amount of time creating that person, getting acquainted. You love them because they're the best and worst parts of yourself....and if you choose, you can kill them off and not have to deal with them again :)
I love writing.