LeBron James erred many times over when he sat on that bar stool at American Airlines Arena nearly two years ago, with Dwyane Wade and Chris Bosh giggling to his left, and boldly promised that multiple championships were in store for the newly assembled Miami Heat. But his greatest blunder from that July afternoon was when he coolly brought the microphone under his well-shaped beard and said, “Once the game starts, I mean, it’s going to be easy.”

The comment doesn’t haunt him nearly as much now that he has claimed his first NBA championship, but James should’ve known when he let that phrase leave his lips that “easy” is never a word that can be used to describe a title run. Even with the unconventional free agent union of three all-stars in their prime — all from the same draft class, and all willing to take less money in order to win — the Heat wasn’t allowed to skip the usual torment required to mold an NBA champion.

And as he sat at the podium on Thursday after the Heat defeated the Oklahoma City Thunder in five games in the NBA Finals, championship T-shirt drenched in Dom Perignon, James acknowledged that the past two years were a more difficult and humbling challenge than he could’ve imagined.

“It was the hardest thing I’ve ever done as a basketball player, since I picked up a basketball when I was 9 years old,” James said. “It’s not easy at all.”

Heat President Pat Riley, the architect of the James-Wade-Bosh merger, claimed his eighth championship ring — one as a player, one as an assistant and four as coach of the Los Angeles Lakers; and now two as an executive (he also coached the 2005-06 Heat). But after famously guaranteeing back-to-back titles in 1987-88, Riley had to wait 18 years to taste glory once again. The struggle kept him from making any bold declarations about returning immediately after the Heat defeated Oklahoma City.

“We believe that we built a team that’s going to be around for a while, and our goal is to hopefully come back every year,” Riley said. “It’s always started out as an upstart, you become a contender, and then one day you might become something special, and that’s what we’re shooting for. All these guys back here have put it on the line.”

Wade was fortunate to win a championship in his third season in 2006, but he wasn’t playing under the pressure to win, since most of it fell on Shaquille O’Neal and other veterans. He caught the league by surprise, supplying a fresh-faced humble superstar for the league to promote and cherish.

In the years that followed, Wade had to hit bottom. Wade failed to get out of the first round, was on a team that finished with the league’s worst record in 2007-08, and had to essentially punt two years of his prime in anticipation of the summer when he could lure both James and Bosh to his team so that they could win together.

The pressure on Wade increased when the Heat became relevant again, but his the-world-hates-the-Heat complaints came across as being a victim of his own fame. He carried the Heat last season in the NBA Finals, as James was admittedly overwhelmed by the moment, and eventually had to step aside for James in order for James and the Heat to maximize their potential.

Wade sacrificed, but at times lost himself, this season. He nearly unraveled against Indiana before having his knee drained and paying a visit to his college coach, Tom Crean. Having to wait six years for another ring made him more appreciative.

“I’m going to enjoy this one a lot more than I enjoyed 2006. When you get there early, you say, ‘Oh man, we’re going to do this again next year.’ This is not guaranteed right here, man,” Wade said. “This process is unbelievably hard, and I don’t care who you put on a team. Obviously, we all expected this to be easier than it was, but we had to go through what we went through last year.”

Bosh was a sobbing, stumbling and collapsing example of that pain and suffering last June, when Miami’s Game 6 loss to the Mavericks caused him to break down in front of the cameras near the locker room. Having never advanced out of the first round in his first seven seasons in Toronto, Bosh didn’t know if he would ever be close to another ring.

Bosh made the largest sacrifice of the trio, subjugating his game to blend with two dynamic scorers and had to endure constant jokes about his toughness. He also had to deal with the fear that his opportunity would be lost this postseason, when he suffered an abdominal strain in the first game of the second round.

“I thought about that moment,” Bosh said of his tearful meltdown, “and that helped me build my will, and it helped me get to this point. . . . Just having the perseverance to keep pushing forward is just a sweet feeling.”

James bolted Cleveland in controversial fashion because he didn’t believe he could win a title by himself with the Cavaliers. But with the hatred and negativity that surrounded the audacious formation of the Super Friends, James tried to prove wrong his detractors last season and instead struggled in a six-game loss to the Dallas Mavericks in the NBA Finals.

“The best thing that happened to me last year was losing in the Finals,” James said. “I knew what it was going to take, and I was going to have to change as a basketball player, and I was going to have to change as a person to get what I wanted. You know, it happened one year later.”