Just when you thought you knew everything there was to know about "Friends," a new book has arrived on the eve of the sitcom's 25th anniversary that offers behind-the-scenes glimpses and fun facts. "Generation Friends" by Saul Austerlitz (available now) chronicles the world of Rachel (Jennifer Aniston), Monica (Courteney Cox), Ross (David Schwimmer), Chandler (Matthew Perry), Phoebe (Lisa Kudrow) and Joey (Matt LeBlanc) from the show's first pitch in the '90s to its newfound internet fandom.
To even the casual "Friends" fan, it might seem like the last few months have been overstocked with anniversary content, from new merchandise to pop-up exhibits to a worldwide tour of that iconic couch. But "Generation Friends" is worth it, not only for the new revelations but for Austerlitz’s ability to turn a phrase that will make you fall in love with the show all over again.
Here are five things we learned about the making of "Friends" from "Generation Friends."
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1. David Schwimmer inspired that infamous 'I take thee, Rachel' slip-up
That memorable moment when Ross mistakenly inserted Rachel's name into his wedding vows to Emily (Helen Baxendale) first came to the writers after the season had started.
Schwimmer was practicing the line "Emily, the taxi's here" but accidentally said "Rachel" instead. Writer/producer Greg Malins told co-creator David Crane they had found the twist the wedding episode needed.
Other storylines were inspired directly by the writers' experiences. Remember Ross' awful pair of leather pants? Writer Adam Chase spent $600 on a similarly tight pair to impress a female friend. The game of catch between Joey and Ross in "The One with the Ball" was inspired by a writers' room game born out of boredom.
2. Writers knew getting Joey and Rachel together was a risky move
Crane said he knew it was "totally wrong" for Joey and Rachel to develop feelings for each other (most of America would agree). Writers argued it would be like having a crush on your sister or playing with fire. But Crane thought the storyline would provide a good roadblock for the ultimate Ross/Rachel reunion and let viewers see a different side of womanizing Joey, so the controversial couple was born.
3. Showrunners considered firing Matthew Perry amid his struggle with drug and alcohol abuse
It isn't a new revelation that Matthew Perry struggled with addiction during his time on "Friends." Director/producer Kevin Bright and series creators Crane and Marta Kauffman grappled with what should be done.
They contemplated firing Perry. They worried starring on a hit TV show wasn't good for the actor's well-being, in addition to being worried that an actor visibly dependent on alcohol and drugs would be bad for the show's well-being.
Ultimately, the showrunners decided the only option was for Perryto stay.
4. Charlie Sheen was super nervous to guest star
Director Michael Lembeck wanted the audience to be surprised when Charlie Sheen made a guest appearance in Season 2 as Phoebe's boyfriend. Sheen missed his first cue to hit the sound stage because he was so nervous: "Friends" was a colossal hit, and everybody from the fans in the audience to the actors invited on set understood it was a cultural phenomenon.
The actor's legs were shaking so uncontrollably, his brother Emilio Estevez had to head backstage and help him calm down before taping resumed.
Other guest star tidbits: Jean-Claude Van Damme showed up 12 hours late to shoot "The One After the Superbowl." Brooke Shields was in that episode, too, acting as Joey Tribbiani's obsessed stalker.
Her then-boyfriend, tennis star Andre Agassi, came to set and caused a bit of a commotion, Lembeck recalled. He said Agassi showed up with a "hulking bodyguard" and snapped at Shields onset after she filmed a scene with LeBlanc.
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5. The whole group nearly moved to Minnesota
The writers discussed a plot that would have forever changed "Friends": moving the setting to Minnesota in the fifth season.
There was no reason for "Friends" to take place in New York – a recurring idea in "Generation Friends" is that New York City is inaccurately depicted on the show. The writers wondered what would happen if one member of the group had a reason to live somewhere else.
Writers pitched a story arc that involved Chandler suddenly getting transferred to Minnesota, prompting the rest of the group to follow and discover a new world of "cheap apartments, friendly neighbors and subzero temperatures."
But accurate or not, New York City was the home of the show. The friends stayed.
This article originally appeared on USA TODAY: 'Friends': 5 secrets we learned about the show in 'Generation Friends'