Dallas Mavericks point guard Kyrie Irving never bought into the whole “Celtics Mystique” phenomenon when he played in Boston.

Irving has since seen the light with the Mavericks facing elimination from the NBA Finals in Game 5 against the Boston Celtics on Monday night at the TD Garden.

Irving didn’t go all-in when he was traded to Boston by the Cleveland Cavaliers on Aug. 22, 2017, a transaction that liberated him from the domineering shadow of LeBron James.

Irving appeared to be the missing piece the Celtics needed while then coach Brad Stevens was building his program around rising young stars Jayson Tatum and Jaylen Brown.

Irving, Brown, and Tatum were supposed to be the latest incarnation of the “Big Three” which had been the hallmark trinity of Celtics’ championship teams dating back to the 1950s.

“When I look back, getting traded here, it wasn’t one of my options, it wasn’t like No. 1 on my list,” said Irving prior to the Mavericks practice on Sunday at the TD Garden.

“So, when the trade opportunity got approached to me, instead of going back and appreciating the Celtics’ history, I just came in with an open mind and just kind of like, all right, I’m just going to go with the flow into this. But I think that was the wrong approach. Just being young.”

Irving’s newfound wisdom and maturity came long after he shot his way out of Boston followed by another failed stint with the Brooklyn Nets. Getting right with the NBA had to wait until Irving joined forced with Mavericks’ head coach Jason Kidd in Dallas, a relationship that has worked out well for both of them. Irving expressed some feelings of regret that he didn’t reach out and do more with his two seasons in Celtics’ green.

“Now being older with hindsight looking back, I definitely would have taken time to know the people in the community and talked to some of the champions that have come before me and actually extend myself to them instead of the other way around, expecting them to be there giving me advice,” said Irving.

“Because they have been through this. They have championship pedigree here. They have shown it for years. They are one of the most winningest franchises in all of sports.

“So, you have to show your respect here. I think that’s what I struggled with initially, was figuring out how I’m going to be a great player here while winning championships and also leading a team and selflessly joining the Celtics’ organization or the cult that they have here.”

The Celtics Mystique was on full display in the championship banners that flew high above the parquet before boisterous sellout crowds but Irving just didn’t see it. The Mavericks delayed the Celtics’ claim for an 18th banner with a 122-84 blowout victory in Game 4 on Friday night at the American Airlines Center.

“That’s what they expect you to do as a player,” said Irving. “They expect you to seamlessly buy into the Celtics’ pride, buy into everything Celtics. And if you don’t, then you’ll be outed.

“I’m one of the people that’s on the outs. I’m perfectly fine with that, you know what I mean. I did it to myself. They don’t welcome me with a warm embrace, even though I know a lot of people in the organization and I’m friends still with some of them.

“But, yeah, doing it to myself. And that’s what I was talking about in terms of accepting the choices. But looking back, I would have shown my respect and have more of a council around me from some of the Boston Celtics that came before me to explain what the pressure is like.”

From his retrospect of lost opportunities and unfulfilled expectations, Irving had some advice for youngsters that are drafted by the Celtics organization or veteran players who are considering Boston as a free agent destination.

“You just expect to have a magnifying glass on you everywhere you go,” said Irving. “I don’t think Boston appreciates being kind of second-class to New York in terms of the media capital of the world, but this is the media capital of the world as well. There’s a lot of history here off the court.

“The community has integrated into the Celtics’ team. That’s probably the best way I could say it. The community is what makes the Celtics great here, the Boston pandemonium. That’s what makes this space so loud and so special, and they take pride in it.

“If any player is coming here, getting drafted here, thinking about coming here for free agency, getting traded here, I just think do your homework and make sure you know what you’re getting yourself into. That’s something I could offer.”