In the moments after the Knicks had completed the unlikely two-game sweep of the Celtics in Boston to start this Eastern Conference Semifinals series, I asked Tom Thibodeau if, despite the concerns that occupy most corners of his mind, he allowed himself a moment to soak in the accomplishment.

A fist pump?

A hug with his players?

A celebration with his fellow coaches?

“That’s the beauty of the playoffs,” he said that night in TD Garden. “You can’t get wrapped up in the emotions of it. I think it’s important, you look forward to the next game but to understand it’s a series. But you have to focus on the games you’re playing. What does it take to win that game? So we know each game, there’s gonna be more force and more aggression and we have to be ready for that. So all that we have to do is make sure that we’re focusing on what it’s going to take to win Game 3.”

It’s not exactly Pat Riley dunking his head into a bucket of water, holding it until the players began to nervously wonder if he was all right and then emerging and saying simply, “To the last breath.” But it let you know that Thibodeau knew the urgency that would be required Saturday for Game 3.

And it seemed the entire city knew, too. While New York might have been poised for a celebration, even the fans knew the importance of what could have been a three-games-to-none lead in the best-of-seven series. So the question is: Why were the Knicks at their lockers after the game wondering aloud why they hadn’t arrived at Madison Square Garden with that urgency and fire in what might have been the biggest game of the season?

I say might have been because now Monday is the biggest game — another chance to put the Celtics on the verge of elimination, to not give back the home-court advantage they stole with the two stirring comeback wins in Boston and now a chance to atone for the hard-to-explain performance Saturday.

“I mean, it's the playoffs,” Josh Hart said. “What we did last game wasn't acceptable. It’s the playoffs, you know? You always dream about being in these situations, so you have to come out with that sense of urgency. And, you know, we can talk about it and all that, but at the end of the day it comes, you know, from that, players' heart and, you know, I think we'll be ready for that.”

Even a day later, it’s hard to explain away the missed opportunity. The loss is understandable. The Celtics are the defending champs and they were better than the Knicks all season long — and even in the Knicks' two wins in Boston, the Celtics had built 20-point second-half leads before the Knicks fought back.

What is harder to understand is that the Knicks couldn’t come out, particularly in that environment, on their home court with 19,812 fans urging them on, to match or top the Celtics' intensity and effort. It’s easy to point to the Celtics' other otherworldly shooting — 6-for-7 on three-pointers in the first quarter to build a 16-point lead and you could even pick apart the Knicks’ strategy, switching less after it had effectively limited Boston in Game 2. But this didn’t seem like a strategy or a shooting problem.

Shots fall or they don’t. John Starks may have shot 2-for-18 in Game 7 of the 1994 NBA Finals but even 30 years later you don't hear anyone criticizing the effort or intensity. Part of it is that everything looks worse when shots aren’t falling and the other team is making everything and the Knicks didn’t believe any more than any fan did that the Celtics were going to roll over down two games. But they did seem to know what it would take to get it right.

"Preparation is a big part of it,” Hart said. “And then, after that preparation is just the competitiveness of the will. And I think that is different for every player. And so I think part of it is the preparation. Part of it is just, you know, the will.”

“I think that's the challenge of the playoffs,” Thibodeau said. “The playoffs are going to challenge you in a lot of different ways. You can get knocked down. You got to get back up. Got to keep fighting. And so you try not to get emotional. The playoffs are a roller coaster. There can be highs and there are gonna be lows. You stick together no matter what, and you keep fighting. That's what it comes down to.”

Saturday, they had the whole city ready to fight alongside them. Now, even if they are home, they may have lost some believers along the way and maybe they’re OK with that — allowing them to recall the “us against the world” attitude that got them in front in Boston, that helped them survive in Detroit.

“The challenge is that you have to be ready for every game,” Thibodeau said. “And I think that's what the playoffs are about. You know, the intensity, the force, the aggression, and you have to understand what goes into winning each game.”

They have another chance Monday night and it shouldn’t take any passionate made-for-the-movies speeches to prove it.