B.J. Penn works in mysterious ways

"The Prodigy" has always been an enigma.

B.J. Penn retired in 2011, citing the unpresentable condition of his face after a three-round brawl with Nick Diaz. He told Joe Rogan in the postfight interview, "I've got a daughter, and another daughter on the way. I don't want to go home looking like this."

Of course, nobody believed him.

That was 18 pay-per-views ago at UFC 137 in Las Vegas. It took less than a year for the reach of obsoletion to hit Hilo. Once Penn began to fade into "was," the old fire began to burn in him again to get back to "is." So he called out upstart Rory MacDonald, the one guy in the welterweight division nobody wants to fight right now.

Is he crazy, people wondered. A lightweight masquerading as a welterweight against a middleweight masquerading as a welterweight? What's he thinking?

The truth is, we never really know what Penn is thinking. He's just B.J. being B.J., and a left-field callout is par for the course. That's why people love him. He's never been explicable.

Yet at the heart of it, the reason he circled MacDonald to end that brief retirement feels like it has less to do with MacDonald than with something broader. It was, to be perfectly cliché, the lure of greatness. What the one-time UFC lightweight and welterweight champion was trying to say on the media call a couple of weeks back is that there's nothing romantic about the past tense.

"I actually texted Dana [White] awhile back and said, 'Dana, I watch all these interviews and all these people talking, and no one says my name when they talk about the greatest fighters anymore … and I really don't like that,'" Penn said. "That was actually a big part of my motivation to come back and look strong and do a good fight here on Dec. 8. I want to be known as one of the best."

And besides, at just 33 years old, Penn shouldn't be a thing of the past. But the real question is, was he ever great to begin with?

There have been times in his career when Penn has realized his potential, yet he could never sustain it. He was just 5-5-1 in title fights in both the welter and lightweight divisions, yet he was in 11 title fights and defended the 155-pound belt three times, and never fought cans. He's had loud moments of greatness (Matt Hughes at UFC 46, Sean Sherk, Diego Sanchez, even the first Georges St-Pierre fight), just as he's had moments of extreme disappointment (usually as a welterweight).

To this day it's hard to know which it's going to be.

Maybe that's why, perhaps more than any other MMA fighter in the sport's aboveground history, Penn is so scrutinized before a fight. We love to gauge his demeanor as much as his midsection. Is Penn interested? Is he in shape? Is he motivated? Did he train hard? Is he running along the bottom of the Pacific Ocean with a large boulder cradled in his arms?

In short -- does he care?

Heading into his fight with MacDonald on Saturday night in Seattle, the indications are that Penn does care. The time away fuels this optimism. There are the visible abs. There is the "thing to prove." He's got motivation from having been forgotten. There's his ongoing rivalry with Tristar Gym and MacDonald's comments.

Those things you can read into.

But more exciting is his sincerity. When we believe Penn is sincere, it means something. It's as good as momentum. It adds to the primal literalness that Penn brings to the fight game, as if there was never such a thing as manufactured hype. It adds to the wild eyes and the lizard tongue and all the face-slapping on his walkout to Israel Kamakawiwo'ole's mix of "Hawaii '78/E Ala E." It is Penn's aura, and the very embodiment of island life and the warrior spirit.

We like that version of him, the old-school Penn. MacDonald calls himself "Ares," the Greek god of war? Penn is war incarnate, son. He is conflict.

That's the B.J. Penn whom fight fans love, and the one he's trying to get back to. Not the one who is 1-4-1 in his last six fights at 170 pounds. And, if history tells us anything, the other Penn is never far away. While St-Pierre guards against complacency like an obsessionist since losing to Matt Serra, Penn has embodied complacency too often, to be sure.

Which will it be? See there, that's the thing: We don't know. But after more than a year away from the fight game, there's something about Penn that transcends his 16-8-2 record and makes you want to believe him.

And that's what returns Saturday night -- Penn's unique air of mystery.