Sitting in a restaurant in Brighton, watching Lebron James speak to Jim Gray while wearing a checkered shirt, wondering why Lebron made such a spectacle out of carving out and spitting on Cleveland’s heart, minutes before Dan Gilbert would write, “I PERSONALLY GUARANTEE THAT THE CLEVELAND CAVALIERS WILL WIN AN NBA CHAMPIONSHIP BEFORE THE SELF-TITLED FORMER ‘KING’ WINS ONE,” I already knew what wouldn’t be finalized until yesterday. The Celtics and Heat would ultimately meet in the NBA playoffs, where reputations would hinge in the balance like a halfway-opened door that could go either way.

“I think they knew it, we knew it, I think everybody knew it,” Chris Bosh said. “It wasn’t if, it was when.”

When has become now, after the Heat finished their breakfast, after the Celtics shook off a late-regular season lull to accelerate past the Knicks, after 82 games exposed the Heat as a team looking to find itself rather than a true NBA juggernaut, after so much anticipation, so much hype and so much good basketball.

Nobody foresaw the regular season unfolding as it did. Nobody foresaw Rondo’s late-season slump, or Kendrick Perkins being traded, or the Heat performing like Brian Scalabrine’s evil step-twin during crunch time. Nobody foresaw the Chicago Bulls stealing the top seed and the Celtics-Heat series getting pushed to the second round. Nobody foresaw Derrick Rose becoming the MVP, or Gary Neal becoming San Antonio’s co-savior, or Kevin Love morphing into a chunky, white, normal-haired Dennis Rodman. But we always knew the Celtics and Heat would meet, and that one team would return home afterward, where they would fish and vacation and lament losing the series that was preordained almost a full year ago, the night Lebron visited the Greenwich Boys and Girls Club.

For the Heat, the Celtics are still a measuring stick. They’re at once the blueprint for three superstars looking to win a championship in year one and the mountain neither Wade nor Lebron nor Bosh has ever scaled. They’re everything the Heat want to be and everything they despise, everything the Heat respect and everything they want to tear down. The Heat promised championships last summer, not one, not two, not three, not seven, and the Celtics are the one Eastern Conference team they always knew would offer real resistance. Somewhere underneath the egos and outward self-assurance, Lebron and Wade must have a small amount of doubt. Beating the 76ers is one thing, but the Celtics have a way of magnifying an opponent’s flaws. They will find Miami’s weakness and they will expose it, and if the Heat are not mentally strong enough they will crumble just like the Cavaliers did last season.

Lebron has seen it before, the way the Celtics respond to adversity and keep pushing forward, the way they can suffocate an opponent with teamwork and execution, the way they can take a sledgehammer to a team’s best-laid plans.  But now he has worthy sidekicks, a team he helped build, and no more excuses. His reputation is on the line, more than any other player in this series, perhaps more than any player ever to lead his conference’s number two seed. When Adrian Wojnarowski writes, “All his excuses have expired, all the artificial rehabilitating of his image is useless. Nothing else matters until LeBron James beats the Boston Celtics,” you want to call it hyperbole. But Lebron has lived under a microscope no other American sports star has ever experienced. He has taken punches from all angles, from Twitter and blogs and the main-stream media, from ex-coaches and ex-players and almost everybody else. He has accomplished everything in his basketball life but one thing, the one thing—ask Kobe Bryant—that can overshadow any public gaffe.

Barring a loss of epic proportions, the Celtics’ reputation is mostly set. They would tell you a Celtic doesn’t become crowned until his second championship, but the truth is these Celtics have done enough to solidify their legacies. History will likely look back upon the Celtics as the New-Age Bad Boys, a group of teammates that didn’t want to be liked by anyone outside their own locker room, a group of winners who lifted their play once the playoffs came calling, who cared not about individual accolades or regular season wins, who cared only about championship rings. Which means this series, for them, sparks a different motivation.

They don’t need to prove anything to anybody. They’re already respected, already looked upon as a team that plays basketball the right way, with a chip on their shoulders and unselfishness in their hearts. But the wax to their championship candle melts away. With a lockout potentially looming, this could be Boston’s last real title shot in the Big Three era. This will soon be Rajon Rondo’s team, and Kevin Garnett, Paul Pierce and Ray Allen will either watch playoff basketball from the confines of their homes, or they will take a lesser role to prolong their careers just for the joy of competing. All great things come to an end, and as the Big Three’s end draws near, they understand the urgency of winning now.

Nine and a half months after Lebron’s announcement changed the NBA landscape, the Celtics will arrive at the destination we knew from day one was destiny. They are finally packing their bags to take their talents to South Beach, for a series we always knew would come, a series that will shape some legacies and potentially seal others, a series this season wouldn’t feel complete without.