Now that the Friends reunion premiered on HBO Max, the world is buzzing about the show again. After they watched the reunion and commented on Matthew Perry's appearance, many fans went back and started rewatching the seasons of the beloved show.

And when you rewatch a show again and again, you start to pick up on the little things that you didn't notice before, especially if you aren't focusing hard on the plot anymore because you've seen it 50 times. Watching closely can result in fans discovering mess-ups, continuity errors, and fails along the way.

The cast shared many laughs on the show, breaking characters many times, but did you notice anything that was a complete fail and should have been more obvious to you? So no one told you life was gonna be this way, but here are all the recent Friends fails fans have just discovered.

12 The One With The Lamp

In this scene where Emily calls Ross for the first time after he said Rachel's name at the altar, David Schwimmer improvised. While talking on the phone, he got so into character that he handed Chandler (Matthew Perry) the first thing he could find, which was the lamp on the table. That was not in the script, and he wasn't supposed to do that so Perry's reaction is real, but is caused a laugh from the audience and a memorable scene.

11 The One Where They Switched Monica

In this scene you see Phoebe and Monica talking at Central Perk, but when it pans to just Phoebe, there is another girl in Monica's place that isn't Courteney Cox. It happens so fast you wouldn't even notice the body double unless you were really looking. Then the camera switches over again, and Cox is back in her place. This realization has just come to light and is one of the most recent findings in the many inconsistencies.

RELATED: Friends: Actors Who Almost Landed Roles On The Show

10 The One Where The Apartment Number Changes

NBC

In season one, Monica and Rachel's apartment has the number 5 on the door, which never made sense in the first place because they walk up a flight of stairs, and apartment 5 would be on the first floor. But that's not the only fail. Two seasons later, the number changes from 5 to 20. Chandler and Joey, who live right across the hall, also go from living in number 4 to number 19. Yes, the mistake was made, but why change it when fans already noticed the number?

9 The One Where That's Not Rachel

Just like the Monica mishap, Rachel was replaced mid-scene. Blink and you might miss it. In "The One With The Mugging," Rachel, played by Jennifer Aniston, bursts in and excitedly tells Joey he scored an audition with Leonard Hayes. He goes to the doorway to talk to her about it and over his shoulder is another actress who is not Aniston. She isn't even wearing the same shirt as her.

8 The One Where Chandler And Rachel Have Met Before

NBC

In the pilot episode, we see Rachel run into Central Perk looking for Monica. When she finds her, Monica introduces her to her friends and brother, who she has met before, but it seems as though Rachel has never met Chandler. However, in later episodes when it flashes back to their college days, it is revealed that Chandler and Rachel actually kissed at a party once. And not only that, but they meet in another flashback episode where they are at the Gellar's for Thanksgiving. Something's fishy here...

RELATED: 15 Photos Showing Rachel Green's Relationship Timelines On Friends

7 The One Where They Forget About Ben

In the first season, Ross divorces his wife Carol, because it turns out she is a lesbian, but she is also pregnant with his child, Ben. Now, Ben (Cole Sprouse) is seen all throughout the series, but it seems as time goes on, Ross just forgets he has a son. Ben does not appear at Ross and Emily's wedding and is not in any of the later seasons. He is mentioned in passing, but we never even see him meet his half-sister, Emma or grow up.

6 The One With The Airport Extras

In "The Last One," Ross is hurrying to the airport to try and stop Rachel from going to France because he is madly in love with her. Now look closely to the background. When Ross goes up to the desk to buy a ticket you see a couple in the back strolling through the JFK airport. Then when Rachel can't find her boarding pass and is looking through her bags for it, the extra behind her are the exact same people, except she is at Newark Airport. How did they get there so fast?

5 The One Where Mike Just Stopped Showing Up

Phoebe is finally happy and gets her happy ending. She finds her Prince Charming in Mike, and they get married in season 10. But after they get married, he is seen in the episode where she wants to change her name, and then for 5 minutes in the first part of the finale. And even then, he just oddly disappears while they are all at Chandler and Monica's apartment. Yes, he wasn't a part of the main six, but he was Phoebe's husband and deserved to be in the final scene. He didn't appear at the reunion either.

RELATED: 20 Photos Showing How Much Courteney Cox Has Changed Since Friends Ended

4 The One Where The Chick And The Duck Just Disappear

NBC

The chick and the duck were crucial parts to the series for a while. They are Chandler and Joey's beloved pets. However, Rachel and Monica could not stand them. The friends even play a game later where they wager apartments or getting rid of the chick and the duck, but Joey and Chandler win so the chick and duck stay. But in later seasons, they are just not seen anymore. The logical explanation is that they died, but why wouldn't that be written in since they were such important parts in the friends' lives?

3 The One Where Ross Doesn't Know His Birthday

NBC

In one episode, Ross is celebrating his birthday in March. Then when Gunther is asking Rachel her birthday, Ross chimes in that his is in December, but Gunther doesn't care and cuts him off. But then in "The One Where Emma Cries," Ross is at the hospital and when Joey is filling out the forms for him, he tells him it is October 18th. So which day is it really? He also supposedly remains 29 for three whole seasons.

2 The One Where Rachel Is Pregnant For Longer Than Usual

NBC

Rachel finds out that she is pregnant at Monica and Chandler's wedding, which we know from a previous episode is May 15. Now she would already be about a month pregnant because Ross reveals he slept with Rachel "about a month ago." She is pregnant for nearly the entirety of season 8, which is about a year in Friends world. In episode 9 of that season, it is Thanksgiving, and Rachel should be about seven months pregnant, but she isn't showing at all. Finally in episode 22, she gives birth, where she tells Ross it is 100 degrees outside, which indicates it is Summer in New York City. But according to the timeline, she should have given birth in January.

1 The One With The Chair Disaster

How could they? In the Friends Reunion, Matt LeBlanc and Matthew Perry revisit their old apartment and sit in their famous reclining chairs. However, fans were mad because they switched sides. The sides were always established on the show and to just disregard that at the reunion made fans upset. They also didn't place them at the correct coordinates. It is unclear if the network did that to see if fans would notice or if it was an honest mistake.

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