The Dolby Theater was filled with laughter and memories on Friday night as the “Glee” cast gathered at PaleyFest to celebrate the show’s six-season run. But before the lights went out in the choir room, the cast took a look back at the first year of the show, when things started to heat up for the New Directions and “Glee” itself.

The cast reminisced about their first mall tour, in between the show’s May premiere and its fall debut, and the thrill of realizing the show had potential to be big. Though it wasn’t until 3,000 fans turned out to an Australia appearance, Lea Michele explained, that “Glee” felt real. “That was the moment that we were all like, ‘This is going to be really incredible.’”

Over the course of six seasons, “Glee” has also collected a small army of guest stars, including Josh Groban, Matt Bomer and Idina Menzel.

Amber Riley revealed that one of the cast’s favorite guest stars was Kristin Chenoweth, who brought a great energy to the set, “and she always brought gifts!” Meanwhile, Jane Lynch said that having Carol Burnett play her mother was “crazy.” “I was so honored that she chose to be in this show,” Lynch said.

Heather Morris remarked at having the opportunity to sing and dance with Britney Spears, something she says “is every girl’s dream.” “In seventh grade, you played her tape, or her CD in your room with your best friend and you’re dancing with her.”

Rather than Morris performing with Spears, “Britney Spears got to dance with Heather,” Darren Criss corrected.

One of “Glee’s” lasting legacies will be its portrayals of a variety of demographics, religions, sexual orientations and disabilities, and the impact it had on its fans and the world of television. Being part of one of the first central storylines following a gay character and his relationship with his father was the most gratifying experience for Chris Colfer. Colfer’s character Kurt came out to his father, played by Mike O’Malley, just four episodes into the show’s first season, to an accepting and loving response.

“We heard from so many fathers and sons who were going though something similar and it doesn’t get better than that. When you can get paid to do something so meaningful to so many people,” said Colfer.

As for being in one of television’s favorite couples, Darren Criss said that “Klaine” is “much bigger than Chris and I. It has much more to do with the appetite of the current audience and really speaks less of us and the writers, but the world we live in now,” he said. “So we’re really the lucky ones.”

The panel also previewed the first hour of “Glee’s” two-hour finale, titled “2009,” taking viewers back to the pilot, filling in the blanks left by the debut episode. The episode flashes back, providing the origins of the New Directions, as well as the beginning of the great Will vs. Sue rivalry. The episode features footage of the late Cory Monteith, who is still very much a part of the show’s sendoff.

Colfer remembered his onscreen stepbrother fondly when asked to share a memory of Monteith, saying that they “always had accidental fun together,” when partnered on press tours. “He was a very special guy,” he said to the already emotional crowd.

Saying goodbye to the show was bittersweet, said Lynch. Meanwhile, Michele recalled that the cast “fell into this big ball, sobbing” when the series wrap on “Glee” was called after Matt Morrison sang the show’s final song.

Before anyone could leave, however, Amber Riley led the entire company to the auditorium, where everyone sat in a circle to share “a beautiful moment,” as Criss puts it. The famed stage was later cut up into pieces and given to the cast as a wrap gift.

The series finale of “Glee” airs March 20 on Fox. Watch the full PaleyFest panel below: