Paul Pierce was one of the most fascinating players to ever wear a Celtics uniform. And one of the most human.

Now that he is gone, traded to Brooklyn with the equally incomparable Kevin Garnett, human nature makes us appreciate him more than ever.

It starts with what the great Boston Globe columnist (and Bath native) Chad Finn perfectly described as his “old man’s game.”

If you’ve played a lot of basketball with men over the age of 35, you’ve seen a very poor man’s version of it at least once at your local gym.

There’s the step-back jumper after a series of head, shoulder, hip and foot fakes.

There’s the deceptively quick first step, a couple of dribbles to the hoop, the shoulder lean to create contact, then, wth his feet barely leaving the floor, the almost nonchalant, over-the-shoulder flip that invariably goes off the backboard and in as he grunts, “And one.”

Don’t forget the impossible angles, surprising strength, and I-only-use-’em-when-I-need-’em leg springs he somehow summons to get a shot off or slice through a crowded lane for a tip-in.

His game was a bit of a throwback to the Russell-era Celtics, but the arc of Pierce’s career in Boston is unique in franchise history.

He came to town in Rick Pitino’s second season, in the next draft after the team lost out on Tim Duncan. He slid to the Celtics at the 10th pick due to questions about his maturity and work ethic, but fans were delighted to have him. He quickly became their favorite as they simultaneously began to sour on team captain Antoine Walker and Pitino.

While the team deteriorated under Pitino, Pierce developed into an All-Star caliber player. He became a folk hero in New England after returning from a near-fatal stabbing incident and playing in all 82 games the next season.

Pitino bailed, and Pierce joined Walker as the faces of the franchise. The Celtics took advantage of the pathetic Eastern Conference and made an unexpected appearance in the conference finals.

A miracle comeback in Game 3 of that series, led by Pierce, established him as the team’s biggest star. Then Walker got fat,  became a one-dimensional player and got traded, leaving Pierce to become the de facto team captain.

He wasn’t ready for the responsibility. In the 2005 playoffs, in Doc Rivers’ first season as head coach, Pierce had a meltdown in Game 6. He was ejected, walked off the court half-naked, and showed up at the ensuing press conference wearing with a bizarre ear-to-chin wrap, and acted like a baby. He played poorly in Game 7 and the Celtics lost at home.

They didn’t make the playoffs the next two years. Pierce made noises about wanting to be traded. He got hurt during the 2006-07 season, languishing on the sidelines as the Celtics essentially tanked in hopes of getting a shot at Greg Oden or Kevin Durant. They missed out again, and some wondered if the franchise player would finally get his wish.

Well, he did get his wish, just not that one. Danny Ainge acquired Kevin Garnett and Ray Allen and saved Paul Pierce’s legacy at the same time.

Pierce became the ultimate team player with his two fellow Hall of Famers sharing the load. His versatility and his ability to do things besides score, though evident in the years when he had to carry the team on his back, complemented his new teammates perfectly.

The 2007-08 season was a bit of a national coming-out party for Pierce. He reveled in the spotlight, playing some of his best games during that season and the playoff run.

The most revisited game the past few days is Game 7 of the conference semifinals against Cleveland, when he and LeBron James went at it in a duel reminiscent of Larry Bird vs. Dominique Wilkins 20 years earlier.

But the game he is largely ridiculed for — Game 1 of the 2008 Finals and the wheelchair — has been on my mind a lot since the trade. Reviewing it on YouTube the other day reminded me why it was a moment that solidified Paul Pierce as one of my all-time favorite athletes.

It happens midway through the third quarter. Pierce gets tangled up with Kendrick Perkins in the rebounding action and collapses to the floor along the baseline, grabbing his right leg.

At first, his face is hidden from camera view. When he rolls over, it is clear that he is in pain. At first the pain seems purely physical. But as trainer Ed Lacerte kneels beside him, it is clear that a lot more is going through Pierce’s mind.

He had waited 10 years for this night. He had survived multiple stab wounds, embarrassing episodes, strange teammates (Walker, Kenny Anderson and Vin Baker lead a long list).

Pierce’s emotions, everything going through his mind, are written all over his face. And at that instant, for a lot of Celtics fans including yours truly, it was like looking in a mirror. We were feeling and thinking many of the same things. The season, the series, Paul Pierce’s career, couldn’t have possibly come to this.

ABC goes to a commercial, of course, and when it returns Pierce is shown being wheeled through the tunnel. He’s stopped wincing, but the mental anguish remains on his face. Celtics fans everywhere know how he feels.

In the locker room, out of camera view, doctors determine Pierce merely sprained the knee. The camera catches him skipping out of the tunnel. The Boston Garden crowd spots him almost immediately, as if they had been staring in that direction the whole time and ignoring what was happening on the court. They stand and let out a roar of relief reminiscent of when Bird returned to the court after bouncing his head on the parquet in Game 5 of the 1991 quarterfinals against Indiana.

Pierce reenters the game to another ovation. Anticipation overwhelms relief as the fans wait to explode when Pierce inevitably hits his next 3-pointer. He obliges with back-to-back threes to give the Celtics the lead for good.

It all seemed silly, maybe even staged, in retrospect. The next day, media and fans, Celtics supporters among them, ridiculed Pierce for the theatrics, even comparing it to the fiasco in Indiana. Some justifiably scoffed that he was no Willis Reed. But many also questioned his toughness, as if a guy stabbed within an inch of his life ever deserved that scrutiny again.

As we all know, the Celtics went on to win the series, and Pierce added the cherry to his legacy with the Finals MVP trophy. He showed some very different emotions holding that trophy, then holding the Larry O’Brien trophy during the banner ceremony the next fall. All of them were raw.

All of them were Paul Pierce to his core, and yet still shared by a lot of the people who, as he put it, stuck with him through the highs and lows.

It was a great ride.

Randy Whitehouse is a staff columnist. His email is rwhitehouse@sunjournal.com. Follow him on Twitter @RAWMaterial33.