In writing my first novel, I learned the value of "intelligent, even fastidious revision" as Oates puts it. The end of the first draft came in at a hefty 115,000 words, not all of which were necessary. Luckily for me, I was born with a very analytical, rational sort of mind (which isn't better than any other sort of mind, but does happen to be well-suited to editing). I'm generally able to read my writing and say, "this particular part is junk. It has to go" and then cut off pieces as mercilessly as if they were unsightly warts or over-long toenails.
And that's exactly what I did with my first novel. After three rounds of revision, I had whittled it down to a significantly sleeker 90,000 words. It was much better off, but the truth is that rational and analytical as I am, the cutting was hard to do. It was necessary to remove some parts I had grown extremely attached to. Although I loved certain phrases and scenes, I had to revise, revise, revise and put the good of the whole book above my emotional investment in a few lines and pages—and also above a certain level of pride. That's incredibly difficult.
I can see what Joyce Carol Oates means by calling revision an art. But more than that, it's a discipline. It's a willingness to sacrifice, and it's a practice in humility. To write well is a gift. But to write well and still be able to admit, "this could be better?" That's how you turn a gift into a way of life.
Today's prompt: Revisit a story you wrote in the past and treat it like it belongs to someone else. How could it be better? Are there unnecessary parts? Questions that need to be answered? Print it out and mark it up with a red pen. Show no mercy. Now go make the changes and turn it into the best story it can be.