While watching Phil Mickelson grab the lead at the PGA Championship, then gag, then rally, then gag again, and finally (in his own words) “gut it out” for his second major championship, a couple of questions popped into the left side of my brain:

Will we ever really understand just how talented Mickelson is? Or is he simply destined to be part of the cast of what historians will look back on as the Tiger Woods Show?

Granted, Mickelson isn’t up for best supporting actor just yet. That honor goes to Vijay Singh, who if he continues to putt like a putz, never will win his fourth major.

But Mickelson needs to play the second half of his career a whole lot better than he’s done with Part One. By winning his second major at age 35, there is a slight ray of sunshine.

Still, it would be overly optimistic to think that Phil could ever catch up to Tiger. Under the best scenario, Mickelson might fulfill the promise predicted by one of the guys who finished second to him at the PGA, Thomas Bjorn.

“He’s not a one-major guy, he’s a 10-major guy,’’ Bjorn said of Mickelson. “And it’s going to be easier and easier for him to win them now.’’

Nice gesture, Thomas, except nothing ever seems to come easy for Phil. And eight more majors might be an over-the-top prediction when you consider that Mickelson took a very long time -- 12 years -- before he finally nailed down the first one at the 2004 Masters.

Then again, who knows? There is a truth in advertising when it comes to the Ford punch line: “What will Phil do next?’’ But even more than Mickelson’s unpredictable nature, there is a precedent among the game’s other greats for “winning old.’’

For example, Ben Hogan claimed eight of his nine majors following his 35 th birthday, while Sam Snead won six of his seven in his late 30s. Jack Nicklaus was more like Tiger, but even the Golden Bear bagged six of his 18 majors after he turned 35.

More recently, Nick Faldo claimed three of his six past age 35; Greg Norman was 43 when he won his second British Open; and Mark O’Meara won both his majors at 41. There were even older major winners, like Nicklaus and Hale Irwin, who at 45 prevailed in the 1986 Masters and 1990 U.S. Open, respectively.

In a way, it’s too bad that the majors have become the single-most measure of greatness. But today’s game is so different in terms of scoring records, playing opportunities, competition and money that the majors remain the one constant in the equation that compares the past to the present.

Mickelson certainly is pumped up for the challenge after moon-walking across the finish line at Baltusrol.

“At 35, I’ve got a number of years left -- good years left -- where my game can continue to improve,’’ he told reporters in the afterglow. “I look at some great players from the past that didn’t start winning big tournaments until their mid-30s, and now I know why.’’

Presumably, Mickelson is referring to pro golf’s learning curve. He certainly had some intelligent insight following his latest breakthrough. Or as he put it: “A week where things didn’t go perfectly the whole time.’’

Yet, lo and behold, he still won.

“I feel like a different player, not because I won the (two majors), I just feel like a different player than 10 years ago,’’ he explained. “The thing I’ve learned the most is how important it is to control the miss, and miss it on the correct side of the course, and take out half of the trouble. . . . Being able to do that has allowed me to make aggressive swings.’’

So Mickelson has changed, yet he hasn’t changed. How this pans out, once again, good question.

He has, probably, eight years and 32 opportunities to go. If Mickelson could win one major every season, which he has done the past two years, he could get to 10. That would position him fourth-best on the list of major championship winners behind Nicklaus, Walter Hagen (11 majors) and Woods (10 and counting).

If 10 majors is too much of a reach, it would be nice to see Mickelson end up somewhere in the next level, which would move him alongside players like Hogan, Gary Player (nine majors), Tom Watson (eight), Bobby Jones (seven), Arnold Palmer (seven), Gene Sarazen (seven), Harry Vardon (seven) and Snead.

Lefty might not look like it at times (especially when he seems lost in Tiger’s shadow), but he has one of the 10 best games of all-time. Now, if he can just prove it.