After loping upstairs in the Ocean Course clubhouse, McIlroy discovered his locker was by the window overlooking the practice green, the beach and the vast, green Atlantic.
Pausing for a moment to take in the view, he thought, "something about this just feels right".
He told caddie JP Fitzgerald and dad Gerry about it downstairs. "I said it to my whole team. It's funny how things work out but I felt from the start that it could be a special week."
And so it was. Over six windswept, rain-lashed and sun-splashed days, a new and thrilling chapter opened for Rory McIlroy and world golf.
Memories of a summer of discontent were long banished the following Sunday as he stood on the 18th tee, seven ahead of his nearest challenger in the final Major of 2012 and master of all he surveyed.
McIlroy turned to Fitzgerald, smiled and said: "Well, we won our first Major by eight, let's do it again."
"And he gets the birdie to do it ... incredible!" the caddie recalled, adding mischievously: "I wouldn't be surprised if Rory knew he had to win by eight to beat Jack's record at the PGA. He is a golf anorak after all."
Jack Nicklaus had finished seven clear of the field in 1980 at Oak Hill, in the penultimate of 18 Major victories which make him the greatest golfer of all time.
McIlroy's tour de force on the Ocean Course and the swathe he cut through golf in the next four months proved beyond reasonable doubt he has the game, the hunger and the temperament to become a legend himself.
That evening, Padraig Harrington astutely predicted: "Rory's only fulfilling his destiny. He won the US Open last year and hasn't had an easy ride of it since then. Yet winning his second Major is going to make things a lot easier for him.
"He's shown that if he brings his 'A' game, everybody else is going to struggle to compete with him."
McIlroy remarked that winning at Kiawah "felt much different" to Congressional. "It felt normal, like this is what I'm supposed to do."
He said life as a Major-winner had taken him "a little bit of a while to handle. There's a little more attention, more pressure, more scrutiny heading into tournaments. Being expected to play well all the time was something I had to adjust to."
However, winning at Kiawah was like firing up the second stage of a Saturn V rocket. It propelled McIlroy to an entirely new level.
Within three weeks, he'd win two of the PGA Tour's prestigious FedEx Cup play-offs, becoming the first man to secure victory on consecutive weeks on the US Tour since Tiger in 2009. McIlroy also equalled the career tally of six wins in America achieved by Seve Ballesteros and Nick Faldo.
Impressively, he was an aggregate 40-under-par for both FedEx Cup events, despite not playing his best golf at the Deutsche Bank and having to iron out a minor swing glitch on Saturday evening in the BMW.
Being able to win with the 'B' game separates the great from the good in golf. After sharing in Europe's Ryder Cup miracle at Medinah, McIlroy emulated Luke Donald by topping the money list in Europe and the US.
He then boosted a flourishing reputation as a lethal finisher by closing with five straight birdies to win the DP World Tour Championship. McIlroy earned €11,904,126 on the course in 2012, including FedEx and Race to Dubai bonuses, boosting his career prize money to €26,277,091.
As a lucrative new contract from Nike, worth $200m-plus over 10 years, came into effect on January 1, his decision to invest in a $9.5m six-bedroom home at Palm Beach Gardens, Florida, didn't trouble the bank manager.
Assuming any teething troubles with his new clubs and ball can be sorted in pre-season testing, golf eagerly awaits his return to the Major championship arena in 2013.
McIlroy strictly takes on the Majors one at a time but, on recent form, he has a golden shot at becoming Europe's first winner of a career Grand Slam in the next seven months, especially with July's British Open being played at Muirfield, the fairest links of them all.
Stockton (71) played a key role in McIlroy's recovery from that Sunday afternoon meltdown at the 2011 Masters to win the US Open at Congressional 70 days later and they still work together.
After 49 years in the profession, Stockton doesn't engage in hyperbole. So when he rates McIlroy as a natural successor to golfing royals Arnie Palmer, Nicklaus and Woods, it's time to take note.
"Arnie Palmer brought the masses to golf with his appeal. Then Nicklaus dethroned him and built a career second to none. I never thought I'd see anyone get close to Jack until Tiger came along ... now we're looking at Rory.
"He's got the modern swing, tremendous power and yet an imagination that's just unbelievable around the greens," Stockton added.
He rates McIlroy's mental alacrity among his greatest assets, saying "Rory's probably the best I've ever seen at such a young age" at listening to advice, understanding it and then applying it. "He just gets it. He's the oldest 23-year-old I've met."
Interestingly, Stockton won one of his two PGA titles at Congressional and captained the US Ryder Cup team to victory in 1991's infamous 'War on the Shore' at Kiawah. Today, he's one of the foremost putting gurus in golf.
Fitzgerald arranged McIlroy's first meeting with Stockton at Quail Hollow, four weeks after that ill-starred Sunday at Augusta, and it took 20 minutes to restore the youngster's rhythmic stroke and confidence in his putter.
Another relatively short conversation with Stockton at Firestone last August proved just as significant in helping McIlroy achieve his record-shattering win at Kiawah.
After becoming Irish golf's first world No 1 by winning last spring's Honda Classic (in the process defying an old-fashioned Sunday afternoon charge by Tiger), the edge went off McIlroy's game during a three-week break before the Masters.
Instead of wreaking revenge on Augusta, he slumped into a share of 40th over the weekend. Pipped by Rickie Fowler on extra holes at Wells Fargo, McIlroy then missed the cut in four of his next five events, including the US Open.
Nothing was spared as McIlroy's game and his personal life came under intense media scrutiny.
Some ludicrously even cited his relationship with girlfriend Caroline Wozniacki among the reasons for his 'slump'. In reality, the Danish tennis ace has a remarkably positive effect on McIlroy's career.
"I think since he met Caroline (in July 2011), Rory's work ethic and his personality have changed to a certain extent," said Graeme McDowell. "Rory's very driven on and off the golf course and, physically, he's beaten himself into great shape.
"Obviously, he spends a lot of time with Caroline, watching her train and compete and training with her," the Portrush man added. "He's become very singleminded in his quest to be the world's best player and I've been impressed with how well he's done it."
With his own frustrations compounded by crushing public criticism, McIlroy's confidence suffered. Despite working Trojan-like to revive his fortunes, he drew little joy from a share of 10th at Portrush, albeit in an uplifting Irish Open, or finishing 60th at July's Open.
Watching on TV, Stockton noted McIlroy's tendency to let his shoulders slump in adversity and had a quiet word with him at Firestone.
"I'm sure there were times Jack Nicklaus got frustrated but you almost never saw it," he explained. "I told Rory to smile more, to look like he's having a good time: 'You don't have to work for a living – you're playing golf!'."
The switch flicked, as McIlroy explained: "Dave just said to me, 'enjoy it. This is what you've always wanted to do since you were a little boy. There's no point in getting frustrated or upset out there'. That's the attitude I had for the next couple of weeks (at Firestone and Kiawah) and it definitely helped."
His resolve was Kevlar tough at Kiawah, especially during Friday's 75 in howling gales, three better than the field average.
Shrugging off his fourth birdie of the day at 13, McIlroy played the shot of the week from the next tee, holding an exquisite four-iron up against a driving cross wind, his ball coming to rest six feet from the dangerous left pin, leading to a rare birdie two.
"It was good to see him so steady emotionally at Kiawah. He was special there. He blew away the field," said Stockton, who was struck by McIlroy's composure after "whiffing" a putt at 15 on Friday. "He'd a 25-footer and got halfway to the hole. It could have been one of the worst putts I've ever seen but Rory came right back and birdied the next."
Pete Dye's beguiling Ocean Course is a beast when it blows. Unlike traditional seaside courses, its fairways don't run between sand dunes but are raised and fully exposed to switching winds.
It has Paspalum grass on its fairways and greens. This West African strain, brought to South Carolina 300 years ago as bedding on slave ships, thrives in heat and the salty ocean environment.
However, it 'grabs' the ball, frustrating all attempts to play it down, beneath the wind, while bump-and-runs into the green don't work either. So players are forced to shape and control their shots through turbulent air.
A bizarre incident at the short par-four third on Saturday suggested fate was with McIlroy after his drive lodged between peeling bark and branch seven feet up a lifeless tree and visible only from the TV blimp.
Directed to his ball, McIlroy dropped back under penalty, pitched over the tree to six feet and maintained momentum with a priceless par. He was four-under through nine and tied for the lead with Singh (on six-under) when a massive storm blew in.
Next morning, after completing a 67, McIlroy was so comfortable in a three-stroke lead, he returned to the house he'd rented and fell fast asleep, having to be roused by his dad for the fourth round.
While Singh (49) simply ran out of steam, McIlroy closed with a faultless 66. The youngest multiple Major-winner since Seve Ballesteros, he finished 13-under, eight ahead of Stoke's David Lynn, remarkably playing his first tournament in America.
The world is in McIlroy's hands.
1 Bubba Watson (April, Masters, 2nd tie hole, 10th at Augusta)
Astounding! Watson's ball rested on pine needles deep in the trees to the right of the fairway, 155 yards from the green. He hit an outrageous hook with his gap wedge, bending the shot 40 yards in the air before it landed on the green and ran out to 14 feet. He beat Louis Oosthuizen to land his first Major title.
2 Justin Rose (September, Ryder Cup, singles, 17th at Medinah)
This monster putt illuminated the greatest day in Ryder Cup history. Trailing by one with two to play, Rose saw Phil Mickelson go close with a deft chip, then holed from 40 feet for a winning birdie. Sportingly, the American led the applause but Rose won out with a birdie on 18.
3 Tiger Woods (May, Memorial, Rd 4, 16th at Muirfield Village)
Host Jack Nicklaus said it was "the most unbelievable, gutsy shot I've ever seen". Woods left himself horribly short-sided in an ugly lie at the par three but played an exquisite lob wedge. His ball trickled down the slope and into the cup, helping Tiger clinch one of three wins in 2012.
4 Louis Oosthuizen (April, Masters, Rd 4, 2nd at Augusta)
The roar from the crowd at this famous par five rose like rolling thunder as Oosthuizen's ball made its long, circuitous journey from the front edge of the green to the hole for an unforgettable Albatross. He hit a four-iron from mid-fairway.
5 Rory McIlroy (August, US PGA, Rd 2, 14th at Kiawah)
Champion McIlroy struck the shot of the tournament on a day from hell. He brilliantly held-up a four-iron in the right-to-left wind, his ball touching down just short of the evil left pin, setting up a rare birdie on this 208-yard par three.
6 Luke Donald (March, Transitions, 1st tie hole, 18th at Copperhead)
Donald eclipsed his rivals in the four-man play-off and leapfrogged Rory McIlroy back to world No 1 thanks to a ballsy 152-yard seven-iron from the right rough to set up his winning birdie.
7 Shane Lowry (October, Portugal Masters, Rd 4, 11th at Vilamoura)
Famous for winning the 2009 Irish Open as an amateur, Lowry landed a splendid eagle on the way to his first victory as a pro. He hit a beautiful 138-yards seven-iron into the wind. It pitched short of the cup and rolled in.
8 Padraig Harrington (June, Irish Open, Rd 4, 8th at Royal Portrush)
The Dubliner turned on the magic for massive, record-breaking crowds by holing a glorious pitch from deep rough 40 yards to the right of the green for birdie.
9 Paul Casey (March, Cadillac WGC, Rd 4, 15th at Doral)
This ace was hilarious, thanks to Scottish caddie Craig Connelly. Thinking he'd won a half share in a Cadillac, Connelly launched into a loud cackling celebration after Casey holed an eight-iron. His face was a picture when he learned he'd been duped.
10 Ernie Els (July, British Open, Rd 4, 18th at Royal Lytham & St Annes)
Adam Scott led by four with four to play but bogeyed every one of them, so Els made a 15-footer for birdie and the Claret Jug. As the third man in five Majors to win with a belly-putter, Ernie's effort hastened the ban on 'anchoring'.