Breaking up is hard to do.

Denver forward Trevor Moore knows all about that. The senior-to-be and a lynchpin on last season’s prolific Pacific Rim Line ultimately decided that the Toronto Maple Leafs’ contract offer was too good to pass up in late July.

“It’s a dream come true to sign,” Moore told me. “There were so many things (that tipped the scales). It’s hard to leave this team, especially at this time of the year because we all thought the roster was set.

“I was excited to come back and win a national championship. But at the same time it’s been a dream of mine to have this opportunity. There are no guarantees in life, and this was a surprise to everyone, myself included.”

Passed over three times for the NHL Entry Draft, Moore nonetheless garnered his second invitation to an NHL prospect camp this summer when the Leafs called. He had attended the New York Islanders’ camp in 2014.

“It’s a place with the most opportunities,” he said. “They’re young, they’re rebuilding. I wanted to see how I fit with their elite prospects so I decided to go.”

Turns out the fit was pretty good, which shouldn’t be a surprise to those who watched Moore paired with Danton Heinen the past two seasons and with Dylan Gambrell last season. Moore skated with Mitch Marner the fourth overall pick in the 2015 draft and Jeremy Bracco, picked atop the third round in 2015.

“The goal was to see how I matched up, and I thought I played well,” Moore said. “It was good to know I could play with guys of that caliber. It was too good of an opportunity.”

Moore’s departure, coupled with  Heinen’s signing with the Boston Bruins in April, means the PRL is down to Gambrell, a sophomore who was selected in the second round of June’s  Entry Draft by the San Jose Sharks. It also means the Pioneers’ offense is down 92 points (and 31 goals) from just those two players.

The line’s success boiled down a couple of basics, said Moore, who finished his DU career with 120 points in 121 games.

“Whether it was with Daniel Doremus the year before or Dylan last year, he and Danton and I would take the time in practice to talk about what we were doing right and wrong in drills. There was a lot of communication and a lot of holding each other accountable.”

Two current Pioneers told me in the past week that neither they nor their teammates don’t blame Moore one bit, with one asking rhetorically, “What is someone supposed to do when you have that kind of offer on the table?”

Moore, who has skated in Denver most of the summer with Pioneers alumni, teammates and some of the incoming freshmen, is bullish on DU’s chances for returning to the Frozen Four this season.

“The team’s still really good,” he said. “The guys they brought in have no lack of skill, and Monty (coach Jim Montgomery) can coach anyone,” he said. “They’re going to be fine.”

Moore, who plans to finish his degree, reflected on his time at DU fondly, saying it was hard to name his favorite memories because there were so many good ones.

When pressed, he said, “The run we made for the NCAA bid my freshman year, when we beat UNO then won the first NCHC tournament.

“Last year, our backs were to the wall at Christmas and then we had that 11-game winning streak. That run was so special. And of course, the Frozen Four trip.”

Sweeping eventual champion North Dakota in a season-altering series in February at Magness Arena also stuck with Moore.

“Both our line and the CBS line were on fire in that first game (a 6-4 DU win),” he said. “The momentum shifts and speed were incredible.”

NoDak has it’s own challenges after sophomore forward Nick Schmaltz left school to sign an NHL contract, joining senior Drake Caggiula and most of its defense in turning pro.

The PRL and CBS lines were fun, but the moral of the story is when it comes to elite college players enjoy them while you can.