It's already hard to comprehend that Friends ended 15 years ago, but prepare for another fact that's going to make you feel really, really old.

Thanks to the power of Netflix, Friends is in our consciousness more than ever at the moment, even becoming the streaming service's most-binged show in 2018.

But with everyone enjoying a good Friends rewatch (and maybe those watching it for the first time), many new observations about the series are being made.

On Twitter on Monday (January 7), user @justlucyslife realised something that's pretty mind-blowing.

Lucy tweeted: "Ok so I was watching Friends last night and Ross was filming a tape for Emma’s 18th birthday and Chandler says the line 'Hi Emma. It’s 2020. Have you woken up from your nap yet?' And it’s just dawned on me that 2020 is NEXT YEAR. Emma would be 18 NEXT YEAR."

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Ok so I was watching Friends last night and Ross was filming a tape for Emma’s 18th birthday and Chandler says the line “Hi Emma. It’s 2020. Have you woken up from your nap yet?” And it’s just dawned on me that 2020 is NEXT YEAR. Emma would be 18 NEXT YEAR. — lucy👄 (@justlucyslife) January 7, 2019

Yes, Ross and Rachel's daughter is now nearly 18! It feels like only yesterday when Rachel discovered she was pregnant at Monica and Chandler's wedding.

Meanwhile, despite the show ending in 2004, the cast are all still earning big bucks every year thanks to re-runs.

According to USA Today, Jennifer Aniston (Rachel), Courteney Cox (Monica), Lisa Kudrow (Phoebe), Matthew Perry (Chandler), David Schwimmer (Ross) and Matt LeBlanc (Joey) each receive 2% of the syndication revenue the show makes.

And if you're about to scoff at 2%, Friends makes Warner Bros a massive $1 billion each year, which means that the main cast members pocket around $20 million annually.

No wonder they don't feel the need to make another season!

All 10 seasons of Friends are streaming now on Netflix.

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