By the end, the final buzzer’s groan filled the old gymnasium. The folks had had their fun and now it was time to catch their trains home. It’s nights like these when if feels like there has never been a faster-emptying arena ever built than Madison Square Garden.

It is starting to sink in that this, in so many ways, is what the season is, what it is going to be, in November and January, in March and April. It’s one thing to talk about the discipline of a full rebuild. It’s one thing to buy in, and to acknowledge that certain things have to be done, and it’s going to be a slow process.

(“Process.” Goodness, that word really doesn’t roll off the tongue, does it?)

In so many ways, this was the paint-by-numbers formula that we have already grown accustomed to, one-tenth of the way into the season.

1. The Knicks play a fervent, furious pace on both sides of the ball.

2. They take a second-half lead, they tease the Garden folks to their feet, they look like they’re going to take out a playoff-caliber team, give their fans a trophy to bring home with them on the LIRR and the subway.

3. One of the Knicks (Tim Hardaway Jr. on this night) has an especially rousing game.

4. They don’t hold onto that lead, and the possessions that are most costly are painful to watch, no matter how few expectations are attached to all of this.

5. The final buzzer groans. The gym empties.

6. Rinse, repeat.

“That’s a tough one,” Knicks coach David Fizdale said. “We have to get better in late-game situations.”

There were moments in their 107-101 loss when it looked like they were going to be OK, because there are always moments when they look that way. The Pacers are good but they are not the Warriors. They don’t keep 40-0 runs tucked away in their back pockets. When Damyean Dotson knocked down a 3 with 4:25 left in the game, giving the Knicks a 95-91 lead, there was a legit burst of glee that greeted the basket and the Indiana timeout that followed.

“We were knocking on the door,” Fizdale said.

That’s the part the Knicks have down. They almost never get blown out. They gave the Warriors quite a battle for about 40 minutes last week. They put themselves in position almost every game to kick that door in.

But something always happens.

In this case, it was the great Victor Oladipo who scored 10 points in the game’s final 4 ½ minutes, the best player on the floor finally overcoming Hardaway and his 37 points. Even so, the Knicks had a chance to rewrite the ending this time. They were down two, 25 seconds left. Indiana’s Bojan Bogdanovic threw up an airball from the top of the key.

The Garden hummed.

And then the Garden sputtered. The airball didn’t go out of bounds. It also didn’t find a set of Knicks’ hands. It found Thaddeus Young’s, and then Young found Oladipo behind the 3-point line with the shot-clock speeding to zero, and if you heard the agitation that accompanied that ball on its way to the basket, the inevitability, you would’ve sworn it was an old Pacer named Reggie taking that shot.

Same result. Same dagger. Different era.

Add another loss to the pile.

“We have to keep battling,” Fizdale said. “The one thing I’m not worried about is their attitude. The come to work every day and put in the work. A lot of this is inexperience, and learning how to dial it in mentally and not get overwhelmed.”

The overwhelming part will come soon enough if, as expected, there are more nights like this one: nights when we can praise the Knicks for their effort, nights when Hardaway (or someone else) goes off on an electrifying jag (though despite his outburst he was a minus-14 for the night), nights when they have a good team in their sights …

And lose anyway.

“We have to figure out how to close games,” Allonzo Trier said.

This was the plan, after all. This was the blueprint. Play the kids. See what you have in Frank Ntilikina (a forgettable night on offense though he was his usual defensive pest), see what you have in the others, get a couple of runs going, get the people cheering, see how it shakes out. They promised it would be fun. Mostly, it has been.

Nobody said it would be easy.