Writing used to be more of a chore. I would sit there, waiting for the words to come, thinking this had to be the strangest type of profession. After all, writers just sit there looking thoughtfully at their computer screens, fooling around on the internet, or finding anything else to do other than writing.
Only recently have I been able to write because it is "fun," accepting both criticism and praise with equal amounts of grace, and oftentimes enthusiasm.
Mostly, this is because I've had years of sharpening my teeth on non-fiction, and so the general task of writing comes much quicker now. Publishing several hundred articles for Demand Studios, explaining complex Unix ideas through email, or ghost writing for clients goes a long way in developing decent writing skills. It also helps to have gone through the process of self-publishing a book. There were tough times, harsh criticisms and even harsher rejections. But in the long run, I was able to make a part-time profession out of it.
Up yours, odds!
The lesson here is that you should never shun the opportunity to hone your fiction writing by slogging out some non-fiction. Take whatever you can get. Sometimes the pressure of meeting deadlines can bring out the best in you, and that can only lead to good things.