From James Franco and Jason Segel's double-casting to NBC's push to create a character for Britney Spears, Paul Feig and company shared show secrets while debuting the upcoming behind-the-scenes A&E doc.

It's been 18 years since Freaks and Geeks was canceled after just one season on NBC. Though it wasn't a ratings hit, the single-camera sitcom's legacy has survived for nearly two decades thanks to a massive cult following and the advent of streaming services like Netflix, where you can binge all 18 episodes whenever you feel the call to revisit William McKinley High.

On Saturday night, fans of the beloved series packed into the Tribeca Film Festival hub to catch the premiere of Freaks and Geeks: The Documentary, an upcoming A&E Cultureshock special directed by Brent Hodge, which offers a no-holds-barred look at the making of the show's first and only installment.

Before the screening, The Hollywood Reporter caught up with Freaks and Geeks creator Paul Feig, who reminisced about the iconic series and its lasting impact.

"It's really cool. Whenever you make stuff, you hope it's going to have some life beyond itself," he said. "But the odds of it happening are very low, especially back then when there was no secondary way to put a show out other than syndication. Once you got canceled, it was like, 'Well, I guess we're just gone forever.' So it was nice to have the first DVDs to come out a few years later and now with streaming services, we can stay alive."

In response to fans' eagerness for a Freaks and Geeks revival amid Hollywood's reboot frenzy, Feig said that an official reunion is highly unlikely. "The chances are probably pretty low," he said of resurrecting the show, which jump-started the careers of its young cast. Freaks and Geeks had six episodes written by executive producer Judd Apatow and co-starred James Franco, Linda Cardellini, Seth Rogen, Jason Segel and Busy Philipps as "the freaks," and John Francis Daley, Martin Starr and Samm Levine as "the geeks."

Feig added of the reboot conversation, "I loved the show — the 18 episodes that we did. And I always get nervous about reunions and that kind of thing. Also, our cast is so famous now. I don't think we can afford them!"

While he's considered the idea of rebooting Freaks and Geeks "with a different cast, possibly another generation," Feig is hesitant, as it could damage the show's position in pop-culture history. As it stands, Freaks and Geeks is revered by critics and viewers alike, often topping "TV shows that were canceled too soon" lists.

"I feel like we did it so well, that part of me just wants to step away," Feig told THR. "But — never say never."

Whether or not Freaks and Geeks ever comes back, fans were thrilled to take a trip down memory lane on Saturday night. Here are eight highlights from the documentary's New York debut and its post-panel discussion with Feig and director Hodge.

1. Most of the episodes were inspired by real-life stories from the writers room.

Writers on the show were asked to fill out questionnaires in order to learn more about each other's high school experiences. As a result, many of the show's scribes saw their awkward teen years directly translated onto the small screen. "Before we started writing anything, we'd lock ourselves into a room for two weeks and would read out loud the questionnaire and then elaborate. We sort of interviewed each other about it, because it's a way for everyone to get completely honest and not hold anything back," Feig said during the panel. "That's where the good stuff comes from."

In fact, Sam Weir's (Daly) infamous Parisian night suit was inspired by a fashion faux-pas made by Feig in high school. "I was really into disco and there was a store in the mall called Silverman's. One day, the guy said, 'Hey, check it out. We just got it in. It's a good jumpsuit,'" he said in the doc. "I put this thing on and the second I walked into school, I realized I made a huge mistake. … So I spent all day walking round in this disco jumpsuit."

2. Getting former NBC executive and show critic Garth Ancier to participate was surprisingly easy.

Freaks and Geeks, which aired on Saturday nights at 8 p.m., fell in the ratings week after week. In the documentary, former NBC exec Ancier is painted as a villain, one who never championed the show as he was mostly unimpressed with its gritty storylines and somewhat uncomfortable material.

Despite his reputation among the cast and crew, Ancier agreed to be interviewed for the film. "I reached out to him on Twitter, actually. I told him, 'Everyone's talking about you and I feel like you deserve the chance to say your side of the story. He said, 'I'd be happy to,'" revealed Hodge, insisting that he "respected" Ancier. "I'm really glad that he did this film."

3. NBC was gunning to get Britney Spears on the show.

In the documentary, Feig and exec producer Apatow said that NBC was incessant about incorporating more uplifting moments — what the network labeled "victories" — into the show. In other words, there was pressure to make the audience smile instead of cringe, no matter if the material was relatable or not.

For the most part, Feig and Apatow dismissed NBC's ideas, including one potential "victory" they were presented with during their short-lived run on the air. "I remember one of the things was that they really wanted us to try and write Britney Spears into this," Feig said during the panel. "They were like, 'She's really popular right now. Maybe she could play a waitress or something!'"

4. The biggest battle was over "The Little Things."

As fans may recall, Freaks and Geeks' 17th episode, titled "The Little Things," explored Ken Miller's (Rogen) infatuation with tuba player Amy Andrews (Jessica Campbell), who was born with ambiguous genitalia.

"'What if his girlfriend ended up having a dick?' is basically what their joke was, and then suddenly Judd’s like, 'Well, wait a minute. Let’s actually look into this thing,'" said Feig, admitting that the episode's first draft, written by Jonathan Kasdan, "became very contentious" because of differing opinions about the subject matter.

"Everybody tried to get us to stop it, but then we all pitched in and started rewriting it and then, like it says in the documentary, Judd took Jessica and Seth into his office, and they started improv-ing," Feig continued. "You don’t want to back down from these stories, and that’s what the network hated."

5. James Franco and Jason Segel were cast at the same time.

Franco and Segel played McKinley "freaks" Daniel Desario and Nick Andopolis, respectively. In the documentary, fans learn that both actors found out they were cast at the same time.

"James went in and then I went in and did my thing and then we waited. And then they told us that we both got cast. We were walking back to the parking lot together and I was so excited. I was trying to figure out how it was going to work," Segel recounted, joking that Franco wasn't worried one bit. "And I said, 'Well, I guess I'll maybe be the goofy one and you'll be the cool one?' And he went, 'Yeah.'"

6. Franco was the hardest actor to write for.

Asked to name the easiest character to write for, Feig was quick to say Lindsay Weir, played by Cardellini. "That's my favorite character that I've ever been involved with because that's the only character that didn't exist. I was an only child and desperately wanted a big sister," he said. "I thought that would be the greatest thing in the world. So I basically invented my perfect older sister in Lindsay."

As for the toughest? Franco's Daniel. "For me, it was Franco probably. Because he was the cool guy," Feig said. "We really did struggle, all of us, with cool guy stories because we could write geek stories all day long. For cool guys, we were writing our cartoon versions of what cool people were. So that's when we brought him into the process to tell us what he would do. I was not cool."

7. Feig is sitting on more behind-the-scenes footage.

"Gabe Sachs, one of our writer-producers on the show, is an avid cameraman and documentarian, and so he was always taking tons of pictures and he was also taking tons of videos. And so when Brent was going to do this documentary, I told him, 'You should reach out to Gabe because I think he's got extra pictures and stuff,'" Feig told THR ahead of the screening. "And Gabe said, 'Oh, I've got all this behind-the-scenes video!'"

A reboot may be out of the question, but Feig said a second documentary is possible — if he can track down his missing tapes. "And, actually, I had a bunch, too, but I can't find it, which is really depressing," he continued before joking, "So there'll be another documentary, soon!"

8. A Freaks and Geeks musical is "just sitting there."

Feig seemed hopeful that he could one day adapt the series as a musical. "I’ve been saying for 15 years I so wanna do the Freaks and Geeks musical," he said. "I just have to write the book for it, but I think it will happen one day because it’s just sitting there, waiting to be done. A musical number of a dodgeball game, come on!"

Freaks and Geeks: The Documentary will air later this year on A&E.