out-run by a 10 outer

Recent $33 buy-in tournament, I was dealt 98 suited in spades on the button. The blinds were 20/40, I limped behind 3 limpers; the big blind raised to 150, and we took the flop 5 handed.
The flop came 5, 6, 7, rainbow [the 7 was a spade] -- I flopped the stone cold nuts, office hours -- a straight from 9 to 5.
The action was checked to me and I bet about 1/2 the pot - $300.
One player called and the turn was the ten of spades. I still had the nuts -- now a ten high straight, and still the best possible hand -- but I also picked up an open-ended straight flush draw. Action was checked to me and I bet about 1/2 the pot -- $600. He check-raised me for all his chips -- about another 1000 (I had him outchipped by about $600) -- and I of course called with the current nuts and the chance to catch the immortals.
He turned over 66 -- he had flopped a set.
The river paired the 10, giving him sixes full and cracking my straight.
On the turn, out of the 44 unseen cards left in the deck (the four cards on board plus my hole cards plus his hole cards is 8 known cards, leaving 44 unknown cards in a 52 card deck), he had 10 outs: any 5, 7, 10 or the case 6. He was about a 3.5 to 1 dog to make his hand, but I'm sure he thought that his set of sixes -- the mark of the beast -- was good and that he didn't need to improve his hand to win. When my hand was turned over, I bet he was pissed, and when the 10 paired, I imagine he about jumped for joy.
Poker -- it's a roller coaster. You can hold the nuts but on the turn of a card, fortunes change hands.