The Celtics’ Ray Allen shoots over Lamar Odom of the Lakers during the first quarter of last night’s game in Boston.

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AP / Elise Amendola

BOSTON — It’s time to give a public thank you to Kevin Garnett.

Would any of this be happening without him, these Celtics in the finals, the Celts in the middle of the sporting eye, the great showdown with the Lakers, the Celtics back to NBA royalty?

Not on your life.

From the moment he arrived here last summer, he changed the culture of the Celtics almost all by himself. The acquisition of Ray Allen instantly made the Celtics a better team, the All-Star veteran with the sweet stroke. Paul Pierce bought into it, too, the same Paul Pierce who had grown discontent, surrounded by too many young players and too much losing, the same Paul Pierce who made no secret last summer that he expected to be traded.

From the first time they appeared together at the news conference, we all knew the Celtics were going to be very different than they’d been the year before, when they had limped to the finish line like some old horse that couldn’t wait to get to the barn — only 24 wins, their only apparent hope to get the No. 1 pick in the draft.

But this?

Sixty-six wins in the regular season.

The NBA Finals.

The Celtics caring about the game again.

Would anyone have believed this?

No one, that’s who. Not even Doc Rivers, the coach.

Rivers has said before that even he didn’t know what he was getting in Garnett. Sure, he knew he was a great player. Everyone knew that. Garnett’s résumé was as impressive as anyone’s in the game, so Rivers certainly knew the addition of Garnett was going to make his team appreciably better.

But he didn’t know about his ability to change the team’s culture, almost by himself.

Not that Pierce and Allen weren’t part of it, too.

“We all knew we were going to have to sacrifice our individual games,” Pierce said after the Celtics had beaten Detroit. “We all knew we would be scoring less.”

Pierce had the most to lose, certainly. Not only was he the captain, he also had been here his entire career. In many ways, he had become the Celtics, the signature face, the one guy who had been here since he was drafted in June of 1998, as all of the names changed around him; coaches, too.

But now he was getting a second chance.

Last Friday night in Detroit all three of them — Pierce, Garnett and Allen — said they had talked it out in the beginning. How it wasn’t going to work unless they all bought into it. How it wasn’t going to work unless they all decided to commit to defense. How it wasn’t going to work unless they all committed to taking advantage of a great opportunity, maybe the last of their careers, to play for a team that had the potential to go deep into June.

So it began.

And from the beginning, the culture did change. Garnett made sure of that.

Everyone knew he was intense. But this intense? Everyone knew Garnett was like a coach on the floor. But this much?

“That’s the thing I didn’t know about him,” Rivers said back in the early weeks of the season.

And it wasn’t just the games.

A lot of NBA players are intense in games. Garnett was intense in practice. Practice? Wasn’t that what Allen Iverson had denigrated in his infamous rant several years ago? Practice? Wasn’t that what too many players merely seemed to give lip service to, trying to preserve their energy in a season where there are too many games?

Not Garnett.

He brought the same energy, the same passion, the same sense of commitment to practice that he did to games. He was a real coach on the floor, visibly pumping up the rookies when they did something good, his constant energy lifting everyone around him.

All that, and a great player, too.

The only knock on him was that he never had been able to take his team to a championship. In many ways, this is an unfortunate rap on any player. Winning a title requires an ensemble, not just a star. It is often the result of many things, including a little luck. Patrick Ewing never won a title because he wasn’t a great player. Patrick Ewing never won a title because his surrounding cast was never good enough.

Garnett’s fate was to have spent his career in Minnesota, out of sight and often out of mind on teams that were limited.

That’s all changed, of course.

This is his moment, his time. He is in the NBA Finals for the first time in his career, on the game’s biggest stage. Good for him. He deserves it.

And for us?

We owe Kevin Garnett a public thank you.

For none of this would be happening without him.

breynold@projo.com