The scene at the Auerbach Center in Brighton felt like the morning after a bad party. People moved a bit more slowly than usual, their eyes still drooping a bit from the night before. And as the smoke was still clearing from the Celtics' second-round exit from the playoffs at the hands of the Milwaukee Bucks, one question lingered in the air: What just happened?

On Wednesday, the Bucks ran the Celtics off the court in a lopsided, season-ending 116-91 Game 5 loss in Milwaukee. The Celtics never really looked like they were in the game, which wasn't that big of a surprise after they had lost the previous three games in the series.

Afterwards, Celtics head coach Brad Stevens didn't mince words about the toll the season took on him.

"I'll be the first to say that this has, you know, as far as any other year that I've been a head coach, certainly been the most trying," Stevens said at a press conference. "I did a bad job. Like, at the end of the day ... as a coach, if your team doesn't find its best fit together, that's on you. And so I'll do a lot of deep dives into how I can be better."

If you have even a basic understanding of basketball and the NBA, you know the lofty expectations for Boston heading into the season. After coming within one game of the finals last year without Kyrie Irving or Gordon Hayward, the general consensus was that Boston could be the team to beat not just in the Eastern Conference, but maybe in the entire league.

That's not how it worked out. The team limped into the playoffs as the fourth seed in the East after a season filled with veterans calling out young players, the attitude of the team and the press while the team struggled to find its rhythm on the court.

Once they got into the playoffs, things actually looked up for the Celtics. They swept the Pacers in the first round and won the first game of the Bucks series on the road in Milwaukee. Then, things fell apart.

The Bucks looked like the better team, outscoring them by an average of just over 16 points in the final four games as Boston became the first team in NBA history to win their first five playoff games and then drop four straight.

Hayward, who returned this fall after a devastating injury in last season's opening game, said this season was disappointing and very challenging for him individually.

"I think a lot of people felt that way throughout the course of the season," he said. "And for me personally, [I'm] just excited to get to an off-season without having to deal with the injury and rehabbing .... I think that's kind of how I move forward, is using this season kind of as some motivation and some fuel, and just looking forward to attacking it."

The big question heading into the summer will be what happens to the Celtics roster. Rumors have swirled that Irving will look to head somewhere besides Boston despite him saying he plans to re-sign with the team.

While no one who spoke to reporters would comment on what Irving's plans were, guard Marcus Smart dispelled any talk that he was bad for the team's chemistry in the locker room.

"That's bullsh**," he told reporters. "I mean, not one of us on this team know what Kyrie's been through. Probably a few amount of people in this world know what Kyrie goes through."

Despite the earlier than expected ending to the season and questions about what happens to Irving, the Celtics have a lot of options. They have the resources to acquire All-Star Anthony Davis, a move that would immediately make them one of the best teams in basketball. At least on paper.

But for now, there's nothing to do for the Celtics but put the 2018-2019 season behind them. For Smart, the season was filled with challenges. His mother passed away in September and he suffered an oblique injury that sidelined him for most of the playoffs.

But as he reflected on the season, Smart took everything in stride.

"I'm holding on fine," he said. "It was tough with everything that I had going on with my family and things. But basketball is what I do to escape, you know? I love doing it and I'm blessed to do it. ... I get to come back, I get to do it again."