Andy North likes how Pebble Beach sets up for Phil Mickelson to complete a career Grand Slam but doesn't think not winning will affect his legacy. (1:41)

"The test of a first-rate intelligence is the ability to hold two opposed ideas in mind at the same time and still retain the ability to function."

-- F. Scott Fitzgerald

PEBBLE BEACH, Calif. -- Nearly 20 years ago, as Payne Stewart rolled his final putt on the 72nd hole of the 1999 U.S. Open at Pinehurst No. 2, Phil Mickelson started slowly walking toward Stewart -- even before the winning 18-footer fell in and Stewart famously threw his right arm into the air.

With a look of resignation, it was as if Mickelson already knew the putt was good.

After Stewart's caddie, Mike Hicks, jumped into his arms in celebration, Stewart cupped Mickelson's baby face in his hands and offered words of encouragement.

"You're going to be a father," Stewart told Mickelson, who arrived in Pinehurst, North Carolina, that week with a beeper tucked in his bag. His wife, Amy, was back in Scottsdale, Arizona, expecting their first child, and Mickelson vowed that if that beeper went off -- no matter when, no matter where he was on the leaderboard -- he was gone.

A few minutes later, while Stewart was being interviewed by NBC's Dan Hicks, he turned to the 29-year-old Mickelson and said, "You're good. You'll win yours. You'll win yours."

Almost two decades later, long after Stewart and five others were tragically killed in a plane crash in a South Dakota field on Oct. 25, 1999, Mickelson is still trying to fulfill his prophecy.

"I probably would have thought I'd have one by now," Mickelson said.

Chris Trotman/Getty Images

Mickelson, who will celebrate his 49th birthday Sunday, will once again try to become the oldest major champion and only the sixth man to complete the career Grand Slam when he makes his 28th start in the U.S. Open this week at Pebble Beach.

Only Jack Nicklaus, Tiger Woods, Ben Hogan, Gary Player and Gene Sarazen won the Masters, U.S. Open, The Open and PGA Championship during their careers.

Mickelson needs to win the U.S. Open to join golf's most exclusive club. He has finished runner-up in the sport's national championship a record six times, most recently in 2013 at Merion, where he had three bogeys over the final six holes and finished tied for second, 2 shots behind Justin Rose.

"I don't think about [the career Grand Slam] a lot," Mickelson said. "I do think about what I have to do to win a U.S. Open. And it's getting increasingly difficult."

It's not as if he needs the final leg of the Grand Slam to validate his career. He is unquestionably one of the greatest and most popular golfers who has ever lived. He has been serenaded by crowds on his birthday, which often falls during the U.S. Open, and is a crowd favorite at courses around the country.

Player, who completed the career Grand Slam with a victory in an 18-hole playoff at the 1965 U.S. Open at Bellerive Country Club, said winning the U.S. Open would "alter his legacy tenfold."

"If any professional today deserves superstardom, it's Phil Mickelson," Player said. "And it's fair to argue that he is at that level even with only five majors and no career Grand Slam because of his relationship with the public. Much like Arnold Palmer, not because of his record, but what he did for the game."

Mickelson has won 45 times on the PGA Tour, including five major championships -- the Masters in 2004, 2006 and 2010, the PGA Championship in 2005 and The Open in 2013. He has earned more than $90 million in his career; only Tiger Woods ($118 million) has made more.

"It's one of those things that, no matter what, he's going to be one of the greatest players that's ever played this game," Woods said. "How he's viewed and whether he wins the career Grand Slam or not, I still think he's one of the best players to ever pick up a golf club."

"It would be pretty special to be part of the elite players that have won all four. To me, that's the sign of a complete game." Phil Mickelson

As Mickelson enters the twilight of his career, the question that keeps coming -- and one he might even be pondering himself -- is can he live without a U.S. Open title? Or is the legacy of becoming the sixth man to complete the career Grand Slam something he needs to justify his career in his own mind?

Can Mickelson desperately want something and yet still be perfectly content if he doesn't get it? Can he, as Fitzgerald suggested, hold two opposing ideas in his mind and still function?

"You know, there's not much I could do right now that would do anything to redefine my career, but there's one thing I could do, and that would be to win a U.S. Open," Mickelson said. "So if I were to do that, it would change the way I view my career because there are only, what, five guys that ever won all the majors. And you have to look at those guys differently. And if I ever join that crowd, and the only way to do that is to win a U.S. Open, it would redefine my career."

It was 20 years ago that Phil Mickelson had one of his best chances to win the U.S. Open, only to be defeated on the final green by Payne Stewart, who died in a plane crash four months later. Steve Schaefer/AFP/Getty Images

THERE HAVE BEEN PLENTY of near misses for Mickelson at the U.S. Open, and perhaps none as painful as the one two decades ago at Pinehurst and the one seven years later at Winged Foot.

In 1999, Mickelson was still searching for his first major championship. He had every reason to skip the first U.S. Open played at Pinehurst No. 2, the iconic Donald Ross course in the Carolina Sandhills.

Amy Mickelson wasn't due with their first child until June 30 -- that U.S. Open ran from June 17-20 -- but doctors ordered bed rest after early complications. Even though doctors gave him the OK to play, Mickelson wasn't thrilled about being thousands of miles from home. He arrived at Pinehurst with a beeper and handed it to his caddie, Jim "Bones" Mackay, and waited to see if it went off.

Player Missing major Byron Nelson The Open Sam Snead U.S. Open Arnold Palmer PGA Championship Lee Trevino Masters Tom Watson PGA Championship Raymond Floyd The Open Rory McIlroy Masters Jordan Spieth PGA Championship Phil Mickelson U.S. Open

Mickelson opened the final round -- the U.S. Open always ends on Father's Day -- trailing Stewart by 1 stroke. It was a dramatic duel over the first 14 holes, with neither player leading by more than 2 shots. On the par-3 15th hole, Mickelson nearly rolled in a 30-footer for birdie, with the ball spinning all the way around the hole before lipping out. He tapped in for par and took the lead when Stewart missed an 8-footer to save par.

On the par-4 16th hole, Mickelson hit his second shot into the thick greenside rough, chipped up and then missed a 6-footer for par. Stewart regained a share of the lead when he made a slick downhill 25-footer for par.

"On 16, when I made bogey, when I had a very easy up and down, that's where that flipped," Mickelson recalled.

With two holes to play, Stewart hit his tee shot on the par-3 17th to within four feet of the cup. Mickelson hit his ball to seven feet.

Stewart's birdie putt went in; Mickelson's missed.

Trailing by 1 shot at the par-4 18th, Mickelson seemed to catch a break when Stewart hit his tee shot into the wet, deep rough on the right side of the fairway. Mickelson hit his drive down the middle and his second shot to 35 feet right of the hole. Stewart was conservative and laid up on his second shot before chipping onto the green with his third.

"Well, there's only five guys that have done it. So that's the hard part. It's just one of those fickle things. You've had some of the greatest champions of all time that have been missing one leg of the grand slam. So for a person who we all know hasn't driven the ball as straight as he would probably like, he's had six seconds in the U.S. Open. That's incredible to be there that many times. He's figured out a way to play well in the U.S. Open. It just happens to be one of those things where he hasn't won, but he's been there. And wouldn't surprise me if he's there again." Tiger Woods

To force an 18-hole playoff on Monday, Mickelson either had to make his long birdie putt or Stewart had to miss an uphill 18-footer. Mickelson's putt slid just past the hole.

"When Payne was lining up that [18]-footer on 18 on Sunday, Mike Hicks comes over to me and says, 'Hey, did you get any of the dots [pin placements] for tomorrow's playoff?' And I was like, 'Huh?'" Mackay told ESPN in 2014.

"And then I turn around, and Payne's putting and the ball goes in the hole. Well, I think any caddie would have looked at it as if it were a real bonus if this goes in."

Mackay declined to be interviewed for this story. His 25-year partnership with Mickelson ended in June 2017.

The only thing going through Hicks' mind at the time was a charity event the next day, which he'd been planning for months. Stewart was supposed to play in the event at Hicks' home course, along with Fred Couples, Paul Azinger and Hal Sutton, to raise money for the North Carolina Children's Hospital.

"When he's over the putt, you don't think ever in a million years the guy's going to make this putt to win," Hicks said. "We're coming back tomorrow for a playoff. This is the honest truth. I'm thinking, 'Who am I going to get to take his place in this outing tomorrow?'"

Of course, Stewart's ball vanished into the hole to win his second U.S. Open title, denying Mickelson his first.

"Obviously, I was happy we won, and I was happy I didn't have to worry about finding somebody to take his place the next day," Hicks said.

Mickelson returned to Arizona, where his daughter, Amanda, was born at 6 p.m. Monday, which would have been only a few hours after a U.S. Open playoff would have ended. Amy Mickelson's contractions started the previous Friday, but she kept them a secret from him until the tournament was over.

Hicks, who now carries Vaughn Taylor's bag, could never have imagined that Mickelson would still be trying to win his first U.S. Open two decades later.

"If we get in, I'd obviously want to win, but I'd be pulling for Phil at Pebble Beach this year," Hicks said. "It would be poetic justice for him to win there."

Tiger has the career grand slam. Phil is still chasing it. Sam Greenwood/Getty Images

THE DRAMATIC FINISH AT PINEHURST was only the beginning of Mickelson's heartache at the U.S. Open.

At Bethpage Black in 2002, in the first major championship ever played at the state park on Long Island, Mickelson opened with rounds of 70 and 73 and was 8 shots behind Woods. But then Mickelson shot 67 on Saturday to move to within 5 shots of the lead.

When Woods had three-putt bogeys on his first two holes Sunday, Mickelson saw an opening. He birdied No. 13 to get to within two, but then hit his tee shot on No. 16 into the deep rough and bogeyed that hole and the next one. He finished 3 shots behind Woods, who won his second U.S. Open title.

At that point in his career, Mickelson was 0-for-40 in majors, a drought that finally ended when he won the Masters in April 2004.

Two months after that Masters win, at the U.S. Open at Shinnecock Hills, Mickelson shared the 36-hole lead with Shigeki Maruyama at 6-under. After limping through his third round, along with nearly everyone else on the sun-banked and wind-whipped Long Island track, Mickelson fell behind Retief Goosen by 3 shots with six holes to play in the final round. But then he birdied three of four holes and took the outright lead with two holes left.

On the par-3 17th, Mickelson hit his drive into a left bunker. When he arrived at his ball, he noticed a small rock directly behind it. (The USGA allowed players to remove stones and pebbles from bunkers when the U.S. Open returned to Shinnecock in 2018.)

"I tried to go behind the rock and underneath it, and it took all the spin off it. It had over-spin on it," Mickelson told Golf Digest in 2018. "It shot past the hole in the one spot I couldn't go, downhill, down wind. It was not a hard shot -- basic uphill bunker shot into the wind. Couldn't have been easier. But that one thing changed everything."

After that bad break, Mickelson, who has long been regarded as one of the best short-game players in the world, did the unimaginable: He three-putted from about 5 feet for double-bogey.

Goosen ended up winning by 2 strokes.

"I got in my car and I had a message from [fellow caddie] Joe LaCava," Mackay recalled. "Whatever you do, don't ever watch a replay of today's golf, which is advice I should have listened to. The greens were impossibly difficult that afternoon. Retief Goosen, to his credit, made putts, and that was tough.

"Phil played really well and lost to a guy who made a bunch of 20- and 25-footers on greens where it was hard to make it from five feet. He played really, really well that day. Nine times out of 10, when he plays that well, you're going to win. And he didn't."

Some of Mickelson's bad breaks have been self-inflicted. When he arrived at the 2006 U.S. Open at Winged Foot, he had three major championship titles. He won the PGA Championship at Baltusrol in 2005 and his second Masters in 2006.

Mickelson led by two after 15 holes of the final round and had a 1-shot cushion standing on the tee box of the 72nd hole. But then he made one of the worst swings of his career, wildly spraying his driver off a corporate hospitality tent way to the left. Making matters worse, he failed to maneuver his second shot around a tree and ended up making a double-bogey to lose to Geoff Ogilvy by 1.

Afterward, Mickelson famously said, "I am such an idiot. I can't believe I couldn't par the last hole."

Even now, the collapse at Winged Foot is probably the missed opportunity that hurts him the most.

"I really should have won that one," he said. "The shot that lingers is not the drive off 18 as much as the 3-iron cutting around that tree. Because if I had not hit the tree, if I had made sure I got it around the green, I would have been up by the green with an opportunity to salvage par with my short game, which was the best it's ever been in my career that week.

"All I had to do was par the last hole. I'll always feel I should have won that one."

Mackay disagrees. He was amazed that Mickelson was even in the hunt, given the way he'd played over 72 holes.

"It wouldn't be in my top three [disappointments]," Mackay said. "He played really well for nine holes on the back nine on Saturday. For whatever reason, he had it for nine holes on Saturday, and the other 63 he did not have it. It's a 72-hole tournament. A lot of people after the fact were treating it like, 'Geez, you've got a 1-shot lead in the U.S. Open. It's over.' It's not the way it works. Hard holes. It's a hard golf course."

Mackay said Mickelson was still searching for his swing when he walked to the first tee for the final round at Winged Foot.

"On Sunday, that was the day he had it the least," Mackay said. "He hit balls and he putted. We were walking over toward the first tee, and he stopped and was hitting shots over the putting green to the range, looking to find something. That's how unsure he was. It wasn't nearly as tough of a loss as some of the others."

Of course, there were more. At Bethpage Black in 2009, Mickelson trailed Ricky Barnes by 6 shots entering the final round. Barnes collapsed, and Mickelson tied Lucas Glover for the lead with an eagle on 13. But then he bogeyed the 15th and 17th holes and finished 2 shots behind Glover.

Four years later, at Merion, Mickelson had a 1-shot advantage going into the final round. He made two double-bogeys in the first five holes and three bogeys in the final six to shoot a 74. He lost to Rose by 2.

"He's still trying to get it," Hicks said. "I think that's the most difficult one to win. Everything has to be aligned, but he's had every chance. He's had his opportunities. It's just a hard one to win."

Phil Mickelson has watched others -- in this case Geoff Ogilvy in 2006 -- hold the U.S. Open trophy, often from up close. Stan Honda/AFP/Getty Images

NOW, AS MICKELSON INCHES CLOSER to a half-century in age, with his face more leathered, his waist surprisingly smaller and his calves more defined, he's trying to do what no other professional golfer has done -- win a major championship at age 49.

Mickelson has won at Pebble Beach a record-tying five times, most recently at the AT&T Pebble Beach Pro-Am in February.

"The difficulty is not the age," Mickelson said. "The difficulty is that when you're in your 20s you feel like you have multiple chances. And when you're turning 49, you're like, 'I've got two more chances, this year, and maybe Winged Foot [in 2020], and that's about it.'

"With that being the only one in the four that I haven't won, and what it would offer me and how I look at my career, I put more pressure on it. That's the difficult thing."

Julius Boros is the oldest man to win a major championship; he was 48 when he won the 1968 PGA Championship and denied Arnold Palmer the only major title The King never won.

Jack Nicklaus was 46 when he won the 1986 Masters. Tom Watson, then 59 years old, just needed a par on the 72nd hole, and he would have won the 2009 Open Championship at Turnberry; he made bogey and lost to Stewart Cink in a playoff.

Maybe Mickelson isn't too old to do it.

"I thought winning them at age 40 was just as easy as winning them at 20," Nicklaus said. "The only difference was that I knew what I was doing at 40 and I wasn't sure what I was doing at 20.

"I think as you get older you accommodate your aches and pains. You accommodate how you make adjustments to what your body is. But you get smarter, too. You should get smarter. If you don't get smarter, you're not progressing in life."

Mickelson hasn't done much since winning at Pebble Beach in February. He has missed four cuts, most recently at the Memorial Tournament two weeks ago. He hasn't finished better than a tie for 18th at the Masters.

"I got off to a great start this year, was playing really well, and I've been in a little lull here," he said. "The game is not far off, but mentally I'm not as sharp as I have been, and I'm not as intense on the course, so I've got to change that a little bit."

He'll also have to change his approach at Pebble Beach. The rough is expected to be much thicker this time, and Mickelson won't be able to bomb his drives the way he did here four months ago. He's more apt to hit irons and hybrids off the tee to keep the ball in tighter fairways. He has to replace power and aggression with patience and accuracy.

"It's a whole different golf course where you're playing almost defense, playing for par first and then trying to make birdie," Mickelson said. "Whereas in February, it is full-bore, all-out, go make birdie on every single hole."

If Mickelson can do that, he just might be in contention in the final round Sunday, near the 20-year anniversary of the beginning of his long and frustrating quest for an elusive U.S. Open title.

And a victory would stamp his undeniable place in history as a career Grand Slam winner.

"Well, there's only five guys that have done it," Woods said. "So that's the hard part. It's just one of those fickle things. You've had some of the greatest champions of all time that have been missing one leg of the Grand Slam.

"So for a person who we all know hasn't driven the ball as straight as he would probably like, he's had six seconds in the U.S. Open. That's incredible to be there that many times. He's figured out a way to play well in the U.S. Open. It just happens to be one of those things where he hasn't won, but he's been there. And wouldn't surprise me if he's there again."

Even if Mickelson doesn't do it, his legacy in golf seems secure.

"It's very self-explanatory," Justin Thomas said. "If he wins, he wins the Grand Slam. But, no, Phil's legacy is Phil's legacy. I think everything he's done and everything he's accomplished is top, I don't know, top couple of all time, regardless if he wins the U.S. Open."

"He's still one of the best players to have ever played," said Rory McIlroy, who needs only a Masters victory to complete the career Grand Slam. "And his record of [45] PGA Tour wins is stellar also. I mean, will people look back on Phil Mickelson if he's won the U.S. Open or not and judge him differently? I don't know. Maybe."

Does winning a U.S. Open title and completing the career Grand Slam really matter that much to Mickelson?

You're damn right it does.

"It would be pretty special to be part of the elite players that have won all four," he said. "To me, that's the sign of a complete game."