Nathan MacKinnon was understandably surly.

The Colorado Avalanche had been eliminated by the Vegas Golden Knights with four straight losses following two wins to open the series. He was being asked a series of questions from the media -- some salient, some startlingly incoherent -- about what went wrong and what happens next. And all MacKinnon could think about was having to hear, "wait 'til next year" instead of feeling the weight of the Stanley Cup in his hands for the first time.

"There's always next year," MacKinnon lamented. "That's all we talk about, I feel like. I'm going into my ninth year next year and I haven't won s---.

"It felt like last year was our first real chance to win, and this year, I thought we were the best team in the league. But for whatever reason, we just couldn't get it together."

There's one reason, actually. The reason you hear from so many players and coaches whose teams finally get over the postseason hump to win the Cup.

You have to lose before you learn how to win.

Not just lose. Teams lose all the time. That Avalanche squad that MacKinnon referenced, from the bubble last summer? They lost. They had excuses. The injuries piled up, to the point where third-string goalie Michael Hutchinson started Game 7 for them. The Dallas Stars team that eliminated them? Pretty good, having later advanced to play for the Stanley Cup.

The loss was a bummer, but an explainable one.

No, what the Avalanche needed was the epic failure. The kind of defeat that shatters a team's collective heart because the players believe they have a series in hand, or because it was ostensibly "their year" to win. The undercurrent of bile in every word MacKinnon uttered after Vegas turfed his team makes you think Colorado just experienced that kind of trouncing.

It's an education. A trial by fire.

"Trust me: you learn more from losing sometimes than you do from winning," said New York Islanders coach Barry Trotz. "It hardens you. You understand the moments more. And you get to a point where you don't want to lose anymore."

Trotz saw this firsthand with the Washington Capitals. The team couldn't get past the second round in his first three seasons there, losing in consecutive playoff series against the Pittsburgh Penguins. The third time was the charm: once they eliminated Pittsburgh in six games in the second round in 2018, you could have crowned them champions on the spot. Things broke their way. Their best players were all having the playoffs of their lives. But along with that, their heartbreak informed their eventual triumph.

This is the path for a lot of championship teams.