Mark Zuckerberg recently shared his first Facebook email ID on Threads, leading to a wave of nostalgia among users. The revelation also highlighted some quirky bits of Facebook’s early history.

Meta CEO Mark Zuckerberg recently added an intriguing tidbit to Facebook’s history. Taking to Threads, Instagram’s chatty sibling, the tech mogul shared the email address he used when he first signed up for Facebook.

The reveal came in response to a playful post from an artist who joked, “I’m ‘you had to have a .edu email address to join Facebook’ years old.” Not one to miss a nostalgic moment, Zuckerberg replied, “Real ones know. First account was mzuckerb@fas.harvard.edu.”

But was Zuckerberg really the first to register on Facebook? Despite being the platform’s most famous face, he wasn’t actually the first to have an account. According to The Guardian, three accounts were created before his, used for testing and later deleted. This technically made Zuckerberg the fourth official user on Facebook. His co-founders, Chris Hughes and Dustin Moskovitz, were next in line, grabbing the fifth and sixth spots.

Zuckerberg’s revelation sparked a wave of nostalgia on Threads. One user recalled, “Pretty sure I took an adult education class at the local university so I could get a .edu account, at least partially so I could meet this requirement. (Still the only college credit I have today.)” Another shared, “I remember being a senior in high school and the thing I was most excited about was graduating so I could finally apply for a Facebook account with my college email. It was all I cared about at the time.”

Naturally, some users couldn’t resist a bit of humour. “So many people will now test that email,” one person joked. Others reflected on the early days of the platform, with one user saying, “I entered college in fall 2004. I remember when we had to switch Facebook from our .edu addresses to the accounts we have now! I think late 2005 or 2006 or so?”

A quick look back at Facebook’s origins shows just how far it has come. Launched on February 4, 2004, as “thefacebook.com,” the site began as a simple directory for Harvard students. Founded by Zuckerberg and his Harvard classmates—Eduardo Saverin, Dustin Moskovitz, Andrew McCollum, and Chris Hughes—the project quickly grew beyond its original scope, evolving into one of the world’s most influential social networks.