And he sounds as though he's just getting started.
"My goal now until the end of the year is to try to win as many golf tournaments as I can," McIlroy said Sunday after his two-shot victory at the Bridgestone Invitational. "It's not to try to finish No. 1 in the world. It's just to get as many titles as possible."
How many can he win?
McIlroy paused and tilted his head, as if counting up the tournaments he has left on his schedule this year.
And that's exactly what he was doing.
"Does the Grand Slam count in Bermuda?" he said playfully of the 36-hole exhibition for major champions. "Does the Ryder Cup count? I feel like with the way I'm playing, there's a few left in me this year."
His confidence has never been higher. His game has never been better.
The victory Sunday was his third of the year and returned him to No. 1 in the world for the first time since March of last year. It felt like a lot longer to McIlroy, who has gone through equipment changes, management changes and an engagement that he abruptly broke off with Caroline Wozniacki.
"It feels good to be back on top," he said. "Hopefully, I can keep it for a while."
The way he has played his last two tournaments, that looks like a distinct possibility. One of them was on the links of Britain. The other was in the parkland of America. Next up is the PGA Championship at Valhalla, and McIlroy established himself as the overwhelming favorite.
"Obviously, Rory is in incredible form at the moment," said Adam Scott, who held the No. 1 ranking for 11 weeks. "He'll be the man to beat next week by the look of things. And I'll be gunning for him, for sure."
McIlroy became the 13th player with a major and a World Golf Championship, and he joined Tiger Woods as the only players to win them in consecutive starts.
Woods wasn't around to see it.
Four months after back surgery, and in his third tournament since his return, Woods injured his lower back when he landed with a thud in the stand from an awkward stance atop a bunker on the second hole. He withdrew after a tee shot on the ninth hole, bending over slowly and struggling to remove the tee from the ground.
It was not clear Woods could play in the PGA Championship next week.
McIlroy heads south to Valhalla with a full head of steam. After a brief celebration with the claret jug, he was determined to move forward and chase more titles over the final four months of the year. He backed it up with a powerful performance on a soggy Firestone course.
"That's the most pleasing thing about this week is not dwelling about what happened at Hoylake," he said. "That's what I'll have to do after this, as well. I've just got to keep moving forward. It's great to have a chance to try to go there to win three in a row. But if you'd have asked me what I'm proudest of this week, it's the mindset that I took into here of not being complacent. I wanted to come here and really contend."
He went into the final round at Firestone three shots behind, and when he got to the fourth tee, he had a one-shot lead. He punched an 8-iron out of the rough and under the limbs, up an elevated green to 3 feet for birdie on the opening hole. He launched a 4-iron from 219 yards to the middle of the green for a two-putt birdie at No. 2. And when Garcia hit into the rough and took bogey on the next hole, McIlroy hit a gap wedge to 8 feet and poured that one into the cup.
The Spaniard never caught up.
McIlroy took the outright lead for the last time with an 8-foot birdie on No. 11 — Garcia missed from the same range — and finished with seven pars. That was enough to close with a 4-under 66 and finished at 15-under 265. He won $1.53 million, leaving him $765 short of Bubba Watson on the PGA Tour money list.
Garcia wasn't at his best and closed with a 71. He's not sure it would have mattered.
"Everybody saw it," Garcia said. "He played very, very well. He drove the ball miles and very, very straight for the most part. He gave himself a lot of birdie looks."
McIlroy said it was the most comfortable he ever felt trying to close out a golf tournament, and this was his 13th title worldwide. Plenty more seem likely to follow.