We must admit we can see how Gossip Girl could have been Serena's brother Eric van der Woodsen, and Schwartz said that the show’s producers even considered Nate Archibald as a potential candidate. However, in the end ‘she’ could only have been one person.

“It had to be Dan, because Dan’s a writer, observer, and could write in different styles,” said Schwartz.

In an interview in 2015, Penn Badgley – who played the character of Dan Humphrey – admitted he wasn’t entirely convinced by the twist ending.

“It doesn't make sense at all. It wouldn't have made sense for anybody. Gossip Girl doesn't make sense!” he told People.

Before concluding: “It made enough sense. He was a writer.”

Images: Rex Features / Warner Bros / CW

Gossip Girl was supposed to have an entirely different ending