You want honest? You sure? It's silly. I have this little ball of fear in my chest, that worries I'll die before I've written/had published all the stories I seem to think I should write. Every time I finish something, a little voice tells me it's not enough. The older I get, the bigger the fear gets. The more I write.
Also, money. And it's incredibly fulfilling and satisfying on some days.
In line with what others have said, I write fiction because an idea or character floods my imagination and I have to work it out on paper. I couldn't let these ideas stew forever. I enjoy applying myself to writing and all the puzzles that go with it, a feeling of full engagement.
I like crafting the words into a story. I used to be a musician, and I guess I need some kind of creative outlet. The standard I have for deciding when I'm done with a sentence, paragraph, whatever, is "How does it sound?" That's why I read those with a distinctive style that lends itself to a flow in the reader's mind: Chandler, McBain, Leonard, to name a few. You can keep the puzzle stories; I write to tell a relatively simple story as eloquently (in its way) as I can.
Once I started keeping a journal (not the diary I kept in high school when I thought I was Anne Frank), I realized how blissfully routine my life is. If I wanted excitement on the page, it would have to be from my own creative process. I love making up backstories for characters and setting them in different situations just to see what happens. Often it's 180 degrees different than my own response would be, which is even more fun. That intrigues me.
I write fiction because it is FUN. Writing non-fiction, due to the stylie restrictions laid down by the publisher to whom I am contrated, is WORK. Then again I recently semi-ghosted a novel for a fewllow who isnt a writer. That was WORK, but when I wrote my parts, that was FUN. If I could be paid as well for my fiction as I am for my non-fiction, I would only write fiction. My friend and mentor, Jack Olsen, told me that I was too talented for non-fiction (HA) and that I should concentrate on fiction and forget writing true crime despite (in his words) writing true crime at its best. So, right now I am writing a non-fiction true crime book AND a screenplay for a flm based on historic fact. Neither has much humor. My fiction has humor.
I've always been pretty good at writing. Starting in second grade, teachers often read my stuff as an example for the rest of the class. I started college undecided on a major, but when my Intro To Creative Writing professor recommended me for a graduate-level course with a visiting Pulitzer winner, I decided on English.
My friends and family, of course, asked the standard question many times: What are you going to do with that? Teach?
I didn't have a good answer. Is there one? I only knew I loved it. If I had it to do over, I would probably major in pre-med, pre-law, pharmacy, engineering...
Anything but English!.
I won some poetry contests in college, got some stout praise for my short fiction, got all As in my English classes, and the profs still often read my work aloud as example.
Many of my friends graduated and got great-paying jobs (it was the 80s. Money, money, money, money...). After I graduated, I worked as a bartender, and did a little freelancing for a major newspaper until I finally got sick of living with my parents and joined the Navy.
I never stopped writing, though. I'm a musician, too, and while in the military I built a home recording studio and tried my hand at songwriting. A few of my songs were published in Nashville, but nothing ever recorded.
After the Navy, I worked as a bartender again and played in bands and still wrote some songs. I always thought that some day, when I had the time, I would crank out The Great American Novel and become instantly wealthy and say nah nah nah nah nah stick what are you going to do with that in your pipe and smoke it you asshole doctors, lawyers, pharmacists, engineers...
I started writing fiction as a serious pursuit three-and-a-half years ago. My first two novels were absolute rubbish. My third got me an agent, and that's where I am now.
Why do I write fiction?
Because my second grade teacher read my work in front of the class.