5 dark and depressing fan theories that will change the way you look at Friends

One fan has gone a step further with the latter, putting forward a particularly dark suggestion which argues that Phoebe's friends were a figment of her crystal meth-addled imagination.

But... but... but... Mike still found her eventually, right?

What if Phoebe wasn't the only one imagining the whole thing? What if every single one of the Friends was actually a patient in an asylum who developed a fictional world to help them cope?

It's not like they don't have reasons to have struggled, after all. Monica was bullied about her weight and had to live in her brother's shadow, Ross has abandonment issues (NOT MARCEL), Joey was the only boy in a house of incredibly strong women and struggled to deal with them all, Rachel tends to self-destruct and has daddy issues, Chandler couldn't cope with his parents' troubled relationship, and Phoebe never recovered from her mother's suicide.

"I'll be there for you" wasn't just a line in a theme tune, it was a group therapy mantra.

Judy Geller sure did seem to have a short fuse when it came to Monica. She was often quick to criticise her only daughter and never tended to soften the blows.

But what if that was because she was feeling a wee bit guilty? What if that's because she had a dark secret? What if it's because Monica wasn't Jack Geller's daughter?

That's the theory posed by some fans, who believe Monica could have been the product of her mother's affair with a mystery man. And her subsequent harsh treatment of her daughter, they suggest, was merely a result of the shame she felt.

Remember when Phoebe and Rachel's apartment catches fire in season six? This theory from Cracked.com suggests the blaze was actually caused by porn barons. Bear with us a second...

Just weeks prior to the fire, Phoebe discovered her sister Ursula had starred in porn films under her twin's name. As payback, Phoebe headed down to the porn company and picked up all the checks her twin sister earned for her x-rated antics, arranging for all future payments to be sent to her "correct address".

Stealing from makers of porn and telling them where you live? Not a wise move, especially as it's clear from the "detailed drawing of a bank floor plan" found in Ursula's purse that Phoebe's sister is mixed up in some serious stuff.

Three episodes later, the apartment catches fire – but just one week before, Phoebe happened to take Rachel to a self defence class. Coincidence? Or did Phoebe know all along that she and her roommate were at risk and attempt to take the necessary precautions?

Remember the way Ben Geller disappeared after series eight? Sure, child actor Cole Sprouse went on to become a twin teen star with brother Dylan in The Suite Life of Zack and Cody, but couldn't they have just re-cast him?

Reddit user smokingcage say no, and for a very important reason: Ross lost custody of his son.

When you examine later episodes of Friends you notice Ross become a lot more anxious, and when Emma's born there's barely any mention of her half-brother. He never even comes to visit her.

And while Ross spends much of his time worrying about his baby girl, he never, ever, ever makes reference to his son. That's because he's too cut up about losing custody of him to his mother, Carol, fans say.