> Show me a world-class writer who doesn't obsess about his writing with every waking moment.
> Show me a master painter who doesn't paint every single chance she gets.
Well, there's Dante Gabriel Rosetti, who decided one day to give up painting and become a poet. While he is remembered more for his paintings than poetry, his poetry carries with it the essence and soul of his paintings as well as the imagery. He decided to paint with words. I don't think he obsessed about writing all the time. As he put it, though, "A sonnet is a moment's monument."[1]
This gets at what I think is an important point though. All of these creative endeavors require real-world knowledge. Hemmingway went out on adventures. For Tolkein, writing fiction was not his day job (teaching about medieval literature and linguistics, however, was). You can see their respective works that the live of the writer and the other obsessions beyond writing are what make the author.
Similarly with programming, yes, it is a technical endeavor and yes it is a creative one. However just like writing the great works of fiction, these don't come out of nothing. They require a context grounded in other knowledge and experience.
[1] http://web.ics.purdue.edu/~felluga/medievalism/areading.html Note that this was the introductory sonnet to "The House of Life" which chronicals Rosetti falling in love, getting married, coping with his wife's death, and finally finding solace in his religious worldview. The poem, despite its abstract nature is full of classical Greek imagery and something one could probably write volumes about. At the same time, it is an exposition on why he wrote poetry, and it provides the framework for fully understanding the hundred or so sonnets in The House of Life in that way. There are love sonnets, and sonnets which, as he puts it "in Charon's palm it pays the toll to Death" (i.e. allowing the dead and the living to begin to move on).