The real skill is ensuring the players think that they're running the show, but all along they're just pandering to your omnipotent desires.
Of course, if the players really don't want to go down the path you want, in any way shape or form, I'm of the opinion that the DM should acquiesce. Although there may be in-game ramifications for such a decision.
Anyway, sort of off topic, I thought I'd post this because it is semi-relevant to the side discussion going on, on players doing stuff out of the blue that throws the DM.
In my last fully fledged campaign, the party got hold of a document that was to become known as the Red Sword Document - because they knew it contained information that would enable them to eventually find the fabled Red Sword of Bright (one of the Seven Glass Swords, but that's neither here nor there).
It took the party about 8 months of game time to decipher it (with some vision type help given to one character who was, unbeknownst to himself, the reincarnation of the document's original author).
Anyway, at one point (before it had been deciphered), while several party members were carrying out some obscure mathematical procedure, one of them suddenly said, "Ware ye Sith."
I said "What?"
He iterated, "Ware ye Sith".
I said "Show me that."
He handed over the Document, together with his arcane maths. Amongst the mess he had come up with the phrase "Ware ye Sith."
Handing back the document, I said, "The sky darkens, and you feel an evil chill. For a moment, you feel as if some terrible, ancient and powerful evil is watching you."
Party in general: Oooooh!
The party continued to use the name "Sith" in vein for a few minutes, until an acid daemon was sent down by his master to teach them some respect.
The Daemon Lord Sith happened to be second from the top in my Heirarchy of Evil for the grand plot line. The party was meant to learn about him maybe a year down the track, real time.
Nowhere in the Red Sword Document was any REAL reference to Sith hidden. The maths were based on baseless assumptions; the result a fluke, the likes of which I have never seen before in my life. No other being in my whole campaign would have reacted to the simple use of his name.
I'm stil amazed by the whole thing.