If you found your 3DS with a used Majora's Mask cartridge in the game slot, but you have no memory of ever buying the game?

Edit: Just saw a comment telling me that there was a Majora's Mask release on the 3DS but not the DS.
That's an error on my part, that's been fixed.

If I make a mistake like this, though, please don't call me names; I wrote this book when I was 13 years old.