1. Lisa Kudrow was afraid of the duck.
2. When the show was first written, Joey and Monica were intended to be love interests.
3. The average Friends episode took five hours to film.
4. Joey and Chandler’s big white dog actually belonged to Jennifer Aniston. A friend gave it to her as a good-luck gift when the show started.
5. Three cast members from The Simpsons made guest appearances on Friends: Dan Castellaneta (Homer), Hank Azaria (Moe/Apu, etc.), and Harry Shearer (Mr. Burns/Smithers, etc.). Also, Hank Azaria, who plays David the scientist, auditioned for the role of Joey twice before the show went into production.
6. The show was originally called Insomnia Cafe. It was then renamed Friends Like Us, and then Six of One before becoming Friends.
7. In the first season, each of the main six cast members received $22,000 per episode.
8. In 1997, they banded together to negotiate a salary increase to $100,000 per episode. It was the first time in TV history that cast members had done this.
9. By the final season, they each got $1,000,000 per episode.
10. Joey plays Dr. Drake Ramoray in a fictional version of the NBC soap operaDays of Our Lives. In real life, Jennifer Aniston’s father, John Aniston, plays Victor Kiriakis on the actual Days of Our Lives.
11. Courteney Cox is actually older than David Schwimmer, despite playing his younger sister.
12. Ross and Rachel weren’t meant to be the central romance of the series. Their storyline was developed because of David Schwimmer and Jennifer Aniston’s chemistry.
13. Monica’s apartment changed from number 5 to number 20 when the show’s writers realised that “5” wouldn’t denote an apartment on an upper level floor in a large block. So they matched, Chandler’s also changed from 4 to 19.
14. The storyline of Phoebe carrying her brother’s triplets was written because Lisa Kurdrow was pregnant in real life.
15. In the opening credits of “The One After Vegas”, which is dedicated to Courteney Cox and David Arquette’s marriage, every cast member has the surname Arquette added to the end of his or her real name.
16. Chandler was written as a character who was awkward around women because Matthew Perry told producers that he himself was.
17. The cast had a huddle before filming each episode to wish each other luck.
18. Bruce Willis appeared in the show for free after losing a bet about whetherThe Whole Nine Yards would be No. 1 in the box office on its opening weekend with Matthew Perry. He donated his fee to charity.
19. Phoebe and Chandler were originally supposed to be supporting characters.
20. David Schwimmer was the first of the main six actors to be cast in the show.
21. Jennifer Aniston was the last of the main six actors to be cast in the show.
Producers originally wanted Courteney Cox to play Rachel, but she asked to play Monica because the character was so strong.
22. The orange couch in Central Perk was found in the basement of the Warner Bros. studio.
23. Ross is 29 years old for three years.
24. Monica and Chandler’s twins are born three minutes and 46 seconds apart.
25. All of the six main characters have kissed each other at one point (if you include alternative “what if?” episodes), except Monica and Phoebe.
26. Like Monica and Chandler, Courteney Cox and David Arquette had trouble getting pregnant.
27. Courteney Cox had to film the scene in which Rachel has Emma just after having a miscarriage.
28. Joey wasn’t written as a dim character. Matt LeBlanc suggested it.
29. The frame around the peephole in Monica’s apartment originally had a mirror in it. It was broken by a crew member during the early stages of filming, but producers thought it looked good so they left it.
30. Friends co-creators Marta Kauffman and David Crane are also co-writers of the show’s theme song, “I’ll Be There for You” by The Rembrandts.
31. When Rachel is trying to find a new officiate for Chandler and Monica’s wedding, she finds a Greek Orthodox priest coming out of the Anastassakis/Papasifakis wedding. Anastassakis is Jennifer Aniston’s family name.
32. When Lisa Kudrow first read the script, she thought Chandler’s character was gay.
33. Giovanni Ribisi plays Phoebe’s brother Frank Jr. in later episodes, but he also has a small cameo in the earlier seasons. He plays a boy who accidentally throws a condom into Phoebe’s guitar case instead of a coin.
34. Winona Ryder and Susan Sarandon were both on Ross’ “celebrity list”. They both later guest-starred on the show as Melissa Warburton and Jessica Lockhart, respectively.
35. The actor who plays Joshua’s father is actually Matthew Perry’s real-life father.
36. Ellen DeGeneres turned down an offer to play Phoebe.
37. Lisa Kudrow had already been guest-starring on Mad About You as Ursula Buffay for two years before Friends aired. They decided to make Phoebe a twin to create a crossover between the two shows.
38. In the last episode, it is mentioned that all six characters have lived in Monica’s apartment. They have all also lived in Joey’s apartment.
39. When the last series ended, Jennifer Aniston and her then-husband Brad Pitt hosted a dinner party at their home. They served bottles of wine that producer Kevin Bright had saved from the first series.
40. When the last series ended, each cast member was given a piece of the sidewalk from outside Central Perk as a keepsake.
I do not take credit for any of the above information.
All info has come from insidehollywood.co