And if we somehow had forgotten amid the prolonged form slumps, the last-minute canceled nuptials and the lawsuits against his estranged managers, he reminded us just why we took notice of him in the first place with a win for the ages over four days at Royal Liverpool.
Only Jack Nicklaus and Tiger Woods were younger when they won the third leg of the career Grand Slam.
And it’s here, ironically enough, that Rory now finds himself: at the intersection of Greatness and being Really Good, From Time to Time.
Or, put another way, he now has a choice to make: Does he want to be the next Tiger Woods or the next Phil Mickelson?
Maybe Woods wasn’t in a good mood after turning in his worst finish ever at an Open Championship — he beat only three players who made the cut — but he was brutally honest in assessing his Nike stablemate on Sunday.
"When he gets it going, he gets it going. When it gets going bad, it gets going real bad," Woods said.
"It’s one or the other. If you look at his results, he’s kind of that way. Very similar to what Phil does.
"He has his hot weeks and he has his weeks where he’s off. And that’s just the nature of how he plays the game. It’s no right way or wrong way. But it’s just the nature of how he plays."
Woods may say there’s "no right way or wrong way," but be sure he doesn’t mean that.
The "right way" is the way he did it and Jack did it: consistent greatness, week in, week out.
Dilettantism, to Woods, is the way Mickelson has done it: a few brilliant weeks and a lot of hapless ones.
McIlroy’s three majors have been as breathtaking as Boy Wonder’s down times in between have been befuddling.
After he won the U.S. Open in 2011 in record fashion, he did not contend at all in the next five majors — missing the cut at the 2012 U.S. Open — but then out of the blue won the 2012 PGA Championship at Kiawah Island, also by eight shots.
After that, he wasn’t a factor in the next three majors, missing the cut at Muirfield last year, before getting a back-door top 10 at the Oak Hill PGA. He had another top 10 at this year’s Masters without ever threatening Bubba Watson and finished well off the pace at Pinehurst.
Now … this virtuoso performance.
So what are we to make of Rory McIlroy?
There’s no doubt he has the arsenal, but does he have the drive, the dedication, the discipline and the ruthlessness to take over from Woods as golf’s new king?
"I definitely hope so," McIlroy said while clutching the claret jug when asked if he expected to become more consistent.
"I’ve really found my passion again for golf. Not that it ever dwindled, but it’s what I think about when I get up in the morning. It’s what I think about when I go to bed.
"I just want to be the best golfer that I can be. And I know if I can do that, then trophies like this are within my capability.
"I’d love to win a lot more and really looking forward to — even though there’s still one major left this year that I want to desperately try and win, I am looking forward to next April and trying to complete the career Grand Slam."
Only five men have won the career Grand Slam: Gene Sarazen, Ben Hogan, Gary Player, Nicklaus and, of course, Woods.
McIlroy will be a short-priced favorite for next year’s Masters. Indeed, he should already have a green jacket if it were not for the final-round implosion of 2010.
Certainly, his game — big right-to-left drives and high, arching irons that land softly to hold Augusta National’s notorious greens — is ideally suited to that major more than any other.
But maybe — just maybe — Tiger will have something to say about Rory’s greatness.
Not the Woods, obviously, who followed an impressive opening 69 here with error-riddled rounds of 77-73-75.
Woods will need to find his old self.
But maybe at 38 he needs something to fire him up, like a kid who’s coming to take all that was his?