OAKMONT, Pa. – Phil Mickelson says his career is “built on failure,” which will raise an eyebrow or two since he has won five major championships, 37 other PGA Tour events and $80 million in prize money.

But when a person turns 46, as Mickelson does Thursday, he is allowed to put his career into whatever kind of perspective he’d like. And he knows what we know: that when he arrives at another U.S. Open, which he has played 25 times, he becomes America’s Runner-Up, a golfer whose astonishing record of six second-place finishes draws attention not to his glorious successes, but to his notorious mistakes.

Mickelson has won three Masters, one British Open and one PGA Championship. He has never won a U.S. Open. So here he comes once again on his quest for the career Grand Slam, and so, too, come the uncomfortable memories: losing to Payne Stewart on the final hole in 1999, hitting his drive off a corporate hospitality tent on the 72nd hole in 2006 (he called himself “such an idiot” for that one), squandering the lead in 2013 on Sunday, which, as always, was Father’s Day, and also that year was his birthday.

“I could BS you and tell you I don't think about it,” Mickelson said of completing the career Slam at his pre-tournament news conference Wednesday at Oakmont Country Club.

“No, I think about it all the time. This is the tournament I want to win the most to complete the four majors. … So I have to put that in the back of my head, but there's no question that starting this year and every year here forward until I ultimately win this tournament, it will be my biggest thought, my biggest focus because I view those players that have won the four majors totally different than I view any other, all the others.”

While Mickelson labels his loss at Winged Foot in ’06 his “most heartbreaking because I was only a hole away (from winning),” his “biggest disappointment” was 2013 at Merion. “I was playing so well. I was leading. I had an opportunity to win at the back nine where I was leading, and I lost the U.S. Open.”

Mickelson said that the following week, "I was very difficult to be around. I just wanted to be alone. And then I kind of came to the realization that I am still playing well and that I have opportunities coming up to play some great golf in the big events.”

A month later, he won the British Open with a stunning final-round 66. “To have my greatest high within a month of having the greatest low of my career is, I think, my biggest accomplishment.”

So that explains it. “My career is built on failure, and that has been a motivator for me, because I think how you handle failure is a huge element to becoming successful.”

If it has happened, it has happened to Mickelson. Last month, he was named in a federal insider trading lawsuit over a 2012 investment he made and agreed to repay $931,738.12 in profits and $105,291.69 in interest. He was not accused of any criminal wrongdoing.

“I've actually known for months what was going to happen, and I'm just glad that it finally is out and over with and behind me,” he said. “So it might have something to do with the fact that it's behind me that I've played well the last two weeks, and I feel like I'm playing stress-free and much better golf. I'm excited that it's behind me.”

Mickelson came to Oakmont earlier this week only to abruptly leave. His second daughter was graduating from eighth grade in San Diego, just as his oldest daughter did three years ago. So just as he flew overnight on his private jet from Merion in 2013, he did it again Monday night, attending the Tuesday commencement and returning in time to practice Wednesday. 

“It's just important for me to be there for that stuff,” Mickelson said. “At 46 years old now, come tomorrow, those are the differences that I'll have where a lot of the young guys in their 20s don't really have to think about yet. But it's also brought me some of the greatest joy in my life, so to be able to be there for that means a lot to me.”

So here we go again. Another graduation. Another birthday. Another Father’s Day. Another U.S. Open, waiting to be won.