For the first time in nearly two weeks, the ghost of Celtics past showed up Saturday night.

And when we say past, we’re just talking about the season’s first couple of months.

In a 117-92 holiday season humbling of the Chicago Bulls, the Boston Celtics played as they did when they were the surprise team of autumn. They moved the ball crisply on offense and dug in on defense. They were first to the floor on multiple loose-ball occasions.

This was, to put it simply, more like it.

“Definitely,” said Marcus Smart. “Our effort was there from start to finish. Everybody did their job. Everybody impacted the game in different ways, so that was big for us. It felt like we played like our old self.”

It was less than two weeks ago when the Celtics began slipping into snowbanks. They lost by 23 in Chicago to these same Bulls, and while Coach Brad Stevens regularly was pointing out that the 22-4 start to the season was a tad illusory, this was a slap in the face that often steels a team and produces better efforts to prove it an aberration.

But as they bounced through three sets of back-to-backs and a calendar week of five games in seven days, there were too many stumbles to ignore.

Sure, the schedule has done the Celtics no favors. They completed a stretch of eight games in 12 nights on Thursday in New York. But Stevens has been absolutely correct each time he’s said, “We’re not using that as an excuse.”

There are at least two reasons why he shouldn’t.

No. 1 is the fact that the Celtics have no one to blame for having played more games than anyone else so far.

When they signed on for a Jan. 11 game in London against the Philadelphia 76ers, they had the right to make special requests of the NBA. The league honored their wish to have extra time on each side of the game, so there are four off days leading in and four more on the other side.

To withdraw that benefit, the Celtics had to have extra games at some point.

The second reason to remain quiet and forge ahead is one that has old-time NBA-types nodding from their rocking chairs. The old Celtics, with Tommy Heinsohn as player and then coach, were fast-break functionaries, and their travel was a great deal more difficult than this. And the team managed without private planes and luxury hotels.

And let us repeat a personal favorite: The Lakers accomplished their league-record 33-game winning streak while playing three games in three nights four times.

So while the NBA schedule is a grind, teams go to great lengths to mitigate the effects. And though the recent troubles haven’t necessarily been indicative of how the Celtics will be when that whole new wood chipper known as the playoffs begins, it’s not something that should be easily excused or passed off.

Stevens said he was pleased with the effort if not the execution in the 102-93 loss to the New York Knicks, but isn’t execution part of effort? If people aren’t getting to the right spots at the right time, doesn’t that have something to do with willingness?

“You’ve got to be able to go out there and focus, especially out of timeouts,” said Smart. “When Coach draws up something, you’ve got to be able to go out there and execute it. That’s where the mental part comes in.

“The schedule’s been rough for us, and you wake up and we had to get here a little bit later because of the Bruins game and then the weather. You take everything into consideration, but you’ve still got to come out here and take care of business.”

We then hit Smart with that stat about the Lakers’ streak.

“Really?” he said. “But that’s it. No excuses. You can’t have excuses.”

The Celtics didn’t need any Saturday night. They produced their largest margin of victory this season. And after taking a two-point lead into halftime, they hit the gas in the third quarter and encountered no real trouble thereafter.

It was, to repeat, more like it.

“Yeah, I think so,” said Jaylen Brown. “I think that’s how we want to play. We can play like that on a consistent basis. It’s just a choice. It’s a long season and we’re a hard-playing team, but I think we can do it.”