Back then, it was Tiger Woods who was making the game look easy as he started to pile up majors. Now it's McIlroy, the 25-year-old from Northern Ireland who produced superior shots with his long game and made all the right putts Friday for a 4-under 67 that gave him a one-shot lead over Jason Day and Jim Furyk.
''When I'm playing like this, it's obviously very enjoyable,'' McIlroy said. ''I can't wait to get back out on the course again tomorrow and do the same thing all over again.''
For Woods, such feelings are becoming distant memories.
He missed two short putts early - one for birdie, one for bogey - and looked as if he should never have tried to play the final major of the year with a sore back. Two birdies on his last three holes only kept it from being worse. Woods shot another 74 and missed the cut in a major for the fourth time.
''I tried as hard as I could,'' Woods said. ''That's about all I got.''
Oddly enough, McIlroy opened with the exact same scores (66-67) as Woods did 14 years ago at Valhalla, when he barely outlasted Bob May in a playoff for his third straight major of the season on his way to an unprecedented sweep of golf's biggest events.
McIlroy, who was at 9-under 133, isn't nearly at that stage. And his competition going into the weekend is a little more experienced.
Furyk, a former U.S. Open champion who was runner-up last year at the PGA, got up-and-down from behind the green on the par-5 18th for birdie and a 68. Moments earlier, Day capped off the best round of a soggy day with a birdie on the 18th for a 65. Day has three runner-up finishes in the majors.
Even so, McIlroy is dangerous when he gets in the lead, especially at a major. He learned his lesson at Augusta National in 2011 when he tried to protect a four-shot lead and wound up shooting 80. He bounced back for an eight-shot win at the U.S. Open, won the PGA Championship by a record eight shots a year later and only last month went wire-to-wire to win the third leg of the career Grand Slam at the British Open.
''My mindset has stayed the same since that day at Augusta,'' McIlroy said. ''If I'm two ahead going into the weekend here, I'm going to try to get three ahead. And if I'm three ahead, I'm going to try to get four ahead. ... I'm just going to try to keep the pedal down and get as many ahead as possible.''
He didn't take his first lead until the par-5 18th hole, the midway point of his round.
McIlroy blasted his driver and couldn't quite see where it went against a cloudy sky.
''Is it good?'' he asked caddie.
''Beautiful,'' was all J.P. Fitzgerald said.
McIlroy hit 4-iron to the front of the green, and his eagle putt rammed into the back of the cup as if it had nowhere else to go. It was a moment where the No. 1 player in the world looked as if he had just seized control of the PGA Championship.
Except it wasn't that easy. In sloppy conditions, McIlroy took bogey on the tough par-4 second hole, and then had to scramble for four straight pars. But on the par-5 seventh, after another big tee shot on the left side of the fairway, he hit a 5-wood over the water to 8 feet, a shot that reminded everyone why he's the class of golf. That was one of the few putts he missed - he still made birdie - and McIlroy finished with a 15-foot birdie on the final hole.
''When he hits the driver that straight and that long, and the short game is incredible, it's very difficult to beat him,'' U.S. Open champion Martin Kaymer said. ''His iron shots, they are very solid. He doesn't miss many golf shots. So you just have to respect it a lot, how good he plays. There's nothing wrong with his game.''
Fowler saw it during the final round at Royal Liverpool last month. He knows what kind of work is left for the guys chasing him.
It can be done. But they might need some help from McIlroy.
''He's the best player in the world right now,'' Fowler said. ''And I would say a lot of that is his confidence right now with the way he's driving the ball. If he continues to drive it, he's going to continue to be in contention at a lot of golf tournaments and win a lot of times.''
Maybe. But the final major is only at the halfway mark.
Day has been battling injuries to his wrist ever since winning the Match Play Championship, and he was pleasantly surprised to be in the hunt at another major. He is explosive, much like McIlroy, minus the experience of winning. The Australian showed that on the final holes with a wedge to 6 feet on the 450-yard 17th hole, and a nifty up-and-down over a bunker on the 18th.
''I'm clearly not the favorite,'' Day said. ''It's going to be tough to beat him. But then again, there's a lot of great golfers behind us that are in form, as well.''
Woods had a one-shot lead over Scott Dunlap going into the weekend at Valhalla in 2000. Of the dozen players behind him that year, only Davis Love III had won a major. This leaderboard is more compelling. It even includes Phil Mickelson, who made eagle on the last hole for a 67 and was three shots behind.
It just doesn't include Woods, who ended a sixth consecutive season without winning a major. And lately, he hasn't even been close.