Hands up, who remembers the "Day One" Xbox achievement? This was a reward that you received for owning the Day One Edition of the Xbox One back at launch in 2013, accessible via a code inside the box.
The achievement has seemingly been made private by Microsoft these days, so it's not easy to find even if you do own it. If you're like Reddit user DrDannny though, it may still be pinned to your profile and still visible that way:
As you can see, just 0.66% of Xbox players own the "Day One" achievement, but it could have been more - a few people took to the comments to reveal they should have had it, but didn't realise they needed to scan in a code at the time!
For those who don't recall the Day One Edition of the Xbox One, it was actually a really cool package! In addition to the exclusive achievement, it included a unique version of the Xbox One controller with the words "Day One 2013" written on it. Multiple games also carried the "Day One 2013" branding featuring extra in-game content.
Of course, you had to be there at the time... so, are you part of the 0.66% of "Day One" achievement owners?