Now that there are six faces on golf's Mount Rushmore, Rory McIlroy should feel like he has reached the very top of the sport.

However, McIlroy's trajectory suggests a wealth of untapped potential and future accomplishments.

Turning 36 next month, he contends he has improved as a player over the past decade, a claim for which there appears to be ample justification.

In his 18 years playing golf professionally, which is half his life, McIlroy had never won three times before May. He feels a great sense of freedom now. He is playing without pressure, and this feeling is separate from the $13.2 million he has already won this year in his six PGA Tour events.

He has clinched the prestigious title of Masters champion.

He now has a locker upstairs in the Augusta National clubhouse. A size 38 green jacket will always be there for him. He also gets a seat at the table for the Masters Club dinner every Tuesday night. This took 11 years to achieve. It must feel amazing.

You could see how relieved McIlroy was because his chest was moving up and down quickly when he put his head down on the 18th green after winning. He said, "The joy came pretty soon after that." This was clear from the look on his face when Scottie Scheffler helped him put on the green jacket.

"What will we all talk about next year?" McIlroy asked, first in Butler Cabin and later to begin his news conference. That shows how free he feels.

Perhaps we could explore the possibility of convening the following month?

With the career Grand Slam now secured, it is not premature to contemplate the prospect of a calendar Grand Slam, especially considering the remaining majors this year appear to favor him.

The PGA Championship is scheduled for next month at Quail Hollow, a course where McIlroy has secured victory four times.

Among the players who participated in a hypothetical exercise last summer, one question was posed: if the current FedEx Cup frontrunner could select the venue for the Tour Championship, where would it be held? McIlroy readily named Quail Hollow.

The U.S. Open is at Oakmont, a difficult course that is good for players who hit the ball hard. This course would likely be good for him, but the last time he played there, he scored 77 in the first round, which took two days because of rain, and he didn't make it to the weekend.

The British Open returns to Royal Portrush in his native Northern Ireland, where McIlroy seeks to redeem himself; at the previous Portrush event, his elevated hopes led him to drive his initial tee shot out-of-bounds, score an 8, and consequently fail to qualify.

He returns with greater autonomy than constraint.

That is still far away, but it shows how the talk about McIlroy has changed. People are no longer talking about what he didn't have, but about what more he can achieve.

Scheffler, present with him in Butler Cabin and during the trophy presentation, provided this perspective Tuesday: "While I don't grasp the experience of being questioned about a career Grand Slam, I have a limited insight into what it feels like to be asked, 'You've achieved this, but you haven't yet achieved that.' It can indeed be quite burdensome for individuals at times."

Brad Faxon, a close friend who helps McIlroy with his putting, said that nothing was stopping McIlroy now and that he could win twice as many major championships. Faxon said, "He can go on to win 10."

Famous golfers Arnold Palmer and Jack Nicklaus once thought that a young Tiger Woods had the basic skills to win ten Masters tournaments, which is as many as they won together. Woods only managed to win five.

When Padraig Harrington made his declaration at the 2011 U.S. Open at Congressional, stating, "If you're going to talk about someone challenging Jack's record, there's your man," McIlroy was still a full round away from securing his inaugural major victory.

Nicklaus holds the preeminent position in golf, having secured 18 major championships. McIlroy, with five, is on par with Brooks Koepka, yet lags behind Woods by a significant margin of ten.

It's easy to get excited. This Masters is like some of the best times at Augusta National, such as when Woods won in 2019, 2001, and 1997, when Nicklaus won in 1986 and 1975, and when Arnold Palmer won in 1960.

But this was hard for McIlroy, not just on Sunday but for the past 16 years. It had been 11 years since he won a major tournament, and while winning the Masters was his dream, in his 16 previous tries, McIlroy only had a real chance of winning on the back nine twice.

Players like Greg Norman, Tom Weiskopf, David Duval, and Ken Venturi were more affected by their experiences, having suffered more emotional and mental difficulties.

McIlroy said two years ago, after he almost won the U.S. Open, that he would have "100 Sundays like this" to win another major tournament. He would have had 1,000 Sundays to win a green jacket, especially because of everything that was important.

McIlroy is now the sixth player to achieve a career Grand Slam, placing him in the esteemed company of Woods, Nicklaus, Gary Player, Ben Hogan and Gene Sarazen. However, only four of these individuals truly 'won' the career slam, as the contemporary understanding of this achievement was not established until Arnold Palmer defined it as such in 1960.

Sarazen is the only other player who has won all four major championships at the Masters. He did this in 1935, when the tournament was held for the second time and was not yet called the Masters. His win was officially known as the Augusta National Invitation Tournament. Green jackets were not given out until 1949, and the Masters Club dinner on Tuesday night did not begin until 1952.

McIlroy is truly the only player to win the last part of the Masters, which is special because it's the only major tournament always played on the same course, making the memories there very strong. This shows how special his achievement was.

To understand how big this achievement is, you should not only look at the few people he has joined but also think about the important golfers who are not in the top group.

Sam Snead holds a share of the PGA Tour record with 82 career victories, a distinction somewhat diminished by his failure to secure a U.S. Open title. Similarly, Phil Mickelson's impressive career achievements surpass McIlroy's, yet he too is conspicuously missing that crucial leg of the Grand Slam – the U.S. Open.

Even though Tom Watson and Arnold Palmer won many tournaments and major championships, neither of them ever won the PGA Championship. Many people think Palmer had the biggest impact on modern golf.

McIlroy started questioning whether he too would join the ranks of the "almost" greats, a doubt the Masters victory has now dispelled, leaving open the question of his ultimate potential.