This memorable post Eleven almost didn’t happen.

Mark Acheson, the actor aptly dubbed “Mailroom Guy” in the 2003 holiday classic, tells PEOPLE exclusively about working on the film — and the one line fans can’t stop talking about.

Acheson, 67, says he was only supposed to have one line in the scene where Buddy the Elf (Will Ferrell) is sent to the mailroom at his father’s workplace. The actor starts his day Eleven Set “the strangest day I can imagine.”

“I called my agent and he said, ‘Listen, they want you to come and do a line with Will Ferrell. Would you like to do that?’ And I said, yes, I would like to do that. I was just supposed to say ‘work release,’ and that was the end of it,” Acheson says.

However, director Jon Favreau decided that Acheson would improvise with the now 57-year-old Ferrell. At one point in the mailroom scene, Acheson’s character tells Buddy that he is 26 years old and has “nothing to show for it.”

Ferrell’s buddy disagrees. “You’re young, you’re so young,” he replies.

The joke, while Acheson and Ferrell were in mail vans, was improvised – and was almost scrapped. The 58-year-old Favreau ultimately ensured that it stayed that way.

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“That’s why the producers wanted to cut the whole scene. I’m like, ‘Who thinks this guy is 26?’ “I mean, seriously. I think I was 46 at the time, and 46 at that, because I’ve never looked young in my life,” Acheson says.

However: “Jon Favreau fought for it. “He said the joke, that’s the funny part, right?” he continues. “He kept me but they, they didn’t want me but he wanted me and thank God for me because it changed my career quite a bit.”

The line about the 26-year-old mailroom worker has been given new life by viral online posts and memes poking fun at the storyline, especially during the holiday season.

“I can believe in an elf from the North Pole. But I definitely don’t think the guy on the left is 26. One of the biggest lies in film history,” one person wrote online.

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“Now more than ever I relate to the eleven mailman guy who is inexplicably 26 years old,” another said on social media. Someone else said they were “cackling” at the fact that Acheson’s character was “supposedly 26 years old.” ”

“The most unrealistic detail in ELF 🎄🎅 is that the guy on the left is 26 years old,” someone else chimed in.

Eleven is available to stream on Hulu and Max, as well as Disney+ and Amazon Prime for Premium subscribers.