PINEHURST, June 10, 2014 (AFP) - The six-time US Open runner-up can become only the sixth man to complete a career grand slam with a triumph at the 114th US Open that tees off Thursday.
He would join Jack Nicklaus, Tiger Woods, Ben Hogan, Gary Player and Gene Sarazen on the select list.
"I feel like the five players that have done that have separated themselves from the other players throughout all time," Mickelson said.
"If I'm able to do that, I would look upon my own career differently. That's why it would mean so much."
The reigning British Open champion has been pondering this opportunity since he captured the Claret Jug last July at Muirfield.
"If I can manage my game and play it smart and just focus on the shot at hand, I feel like I'll give myself a good chance," Mickelson said.
But he was dreaming of a US Open triumph long before his legacy of near-misses, which began in 1999 at Pinehurst when he was runner-up to the late Payne Stewart.
Moments after the emotional victory, Stewart grabbed Mickelson and told him that he would win future US Opens and that what was most important was his becoming a father, which happened hours later with the birth of daughter Amanda.
Four months later, Stewart died in an airplane crash.
Fifteen years later, the moment still resonates with Mickelson.
"It would really mean a lot to me... to do it right here where Payne and I had this moment where he we talked about fatherhood but he also talked about winning future US Opens," Mickelson said.
"Although I haven't won one yet, I'm still fighting hard and this would be a great place to break through and do it."
Mickelson also finished second at US Opens in 2002, 2004, 2006, 2009 and last year.
"The expectations of me looking forward to this event for almost a year now and the history that I've had and how much it would mean to me to win here with what happened with Payne Stewart and my child, that makes it more difficult as well," said Mickelson.
"Pinehurst has so many great memories for me, even though it's not a place that I have won. I'm certainly trying to change that this week."
- Close calls a positive sign -
The US left-hander, who turns 44 on Monday, is trying not to look at this as a last chance, but he admits it might be his best one.
"The biggest thing for me is that I look at those close calls as a positive sign for having given myself so many opportunities," Mickelson said.
"And I believe that I'll have more opportunities. When I do, hopefully the experience that I've had in the past will allow me to handle it better in the future."
Mickelson, who has not cracked the top 10 in a US event this year, will adopt a claw putting grip this week to better handle Pinehurst's formidable greens.
"Everything about Pinehurst provides me the best opportunity," he said. "I don't want to get overly excited, because the pressure of a US Open and having not been in contention, that's going to be a challenge for me.
"The flip side is that I tend to do well when it's least expected."