There are stories you read once, nod approvingly, and then promptly forget both the title and the author, because you don't realize at the time you're going to be quoting that work for the rest of your life. As, for example, the one I read in (I think) Analog years ago, where a man realizes that the bureaucratic system for rewarding excellence in science and technology might as well have been created by hostile aliens to keep our technology backwards. He mentions this idea to a colleague who enthusiastically promotes it -- and finds himself admired, feted, promoted, organizing conferences on the notion . . . and not actually getting anything substantive done with it. Particularly nice was that, though it was never explicitly stated, by story's end the reader had reached the conclusion that the system was created by hostile aliens, and doing a bang-up job of holding back progress as well!
Something like that happens in literature too. When Doris Lessing heard she'd won the Nobel Prize, she snapped, "Oh, Christ!" She just wanted to write, and here the world was heaping distraction on her head, and she was going to lose a couple of months dealing with it all.
I am far from being as successful as Ms Lessing. But I must be doing pretty well, because I keep getting invitations to write incidental nonfiction -- guest of honor profiles for convention books, introductions for collections, and the like -- and, believe me, they take up a lot of time.
Nor are they things I can turn down. An essay on R. A. Lafferty? An introduction for Tom Purdom? A blurb for Gene Wolfe or Eileen Gunn? How could I not want my name associated with these guys? Just being asked is like receiving a little medal of merit. I'm working on three such at the moment.
I say all this not in order to whinge, but to advise young writers: Right now, while nobody is asking, work on your non-fiction skills. Teach yourself to think clearly and to write swiftly and well. You'll thank yourself for that, down the line.