Disappointing end shouldn't overshadow Celtics' incredible turnaround

BOSTON -- It's okay to be disappointed with the Celtics. It's okay to be a mad over how they played to close the NBA Finals. 

It's going to take a while to get over the end of the season. Watching the Warriors celebrate on the TD Garden floor after a painful defeat in Game 6 is not the way this was supposed to go.

The Celtics had an opportunity to bring home a banner and they folded in the end. They lost three straight to end their season. Jayson Tatum couldn't hit a shot, and no one seemed to be able to hang on to the basketball over those three defeats.

When it came time to punch back, the Celtics just didn't respond. Instead, they continually beat themselves.

They collapsed in Games 4 at home. They let a fourth quarter lead slip away in Game 5. Then with their backs against the wall heading into Game 6, a position the Celtics thrived in for much of the postseason, they fell flat after a hot start. Now an otherwise promising and uplifting season is over.

It stinks. It stings. And those feelings aren't going to go away for a while. 

The Celtics just weren't ready for the spotlight of the NBA Finals. Even after they took 1-0 and 2-1 leads in the series, they didn't look ready to take that next step to claim a title. They were, far too often, their own worst enemy.

It's was a disappointing end. But hopefully, this is really just the beginning. 

In these dark times that follow a crushing defeat, think back to where the Celtics were in early January. They were a dysfunctional bunch blowing leads to the New York Knicks. (Now that is a low.)

Now think of what they became as they rolled through the NBA In the second half of the regular season. The elite defense. The incredible ball movement. The insanely tough postseason path, from the gratifying first-round sweep of the Nets to a pair of Game 7 wins to reach the Finals.

The growth the Celtics displayed throughout the regular season and the playoffs was nothing short of incredible. They cut out the selfish ISO ball and became a team. They won a lot of basketball games over the last six months, and were one of the last two teams standing this summer.

Coming up short in the end hurts, but the future is indeed bright. Or at least bright if the Celtics continue to make it bright. The core and the foundation is in place, with Tatum and Jaylen Brown the pillars of the franchise. Robert Williams will only get better as an impact player on both ends. Al Horford will be back to give more leadership, albeit another year older and with a lot more miles, and Marcus Smart will continue to lead the defense.

There isn't much that Brad Stevens and Ime Udoka have to do this offseason, but they can't get complacent. Stevens needs to bring in another guy who can knock down shots and give Udoka a much better -- and deeper -- bench. Udoka needs to figure out a way to generate offense consistently when Tatum or Brown struggle.

Though Tatum was nowhere near a superstar against Golden State, and was outplayed by Andrew Wiggins for large stretches, he still put together a pretty incredible playoff run to build off. He led everyone in points and assists. He had his 46-point masterpiece in Game 6 against the Bucks, and then earned Eastern Conference MVP honors. He knows he wasn't great in the Finals, and those 100 turnovers in the playoffs will be on the forefront of his mind throughout the summer.

He's only 24, and he will continue to get better. So will Brown, who showed he was capable of taking over games. So will Williams, who when healthy, can make opposing offenses disappear. And so will Udoka, who is coming off a trip to the Finals in his first year as a head coach.

The Celtics experienced some extreme highs the last six months, and now they have a summer to think about a crushing low. It will fuel them to come back stronger and better. 

They'll have to, because other teams in the East will get better this offseason. They cannot go into next season thinking they can just show up and make it back to the Finals. That isn't how it works. 

But there should be a lot of optimism surrounding the Celtics. They are going to be in the contention conversation when the fall arrives, and should be for years to come. Now they need to figure out what it takes to get to that next level, the level that the Warriors reached to capture their fourth title in the last eight years.

The agony of defeat will be there for a while, but don't let it ruin your summer. The Celtics will be back soon enough, and they should return even more motivated and a lot better than the team that left the court on Thursday night.