The bothersome button

Bought a pair of jeans the other day, only to find when I got home that the button was missing. As my luck always goes, this was the last pair in my size and the store offered to set a new button in, free of charge. So this morning, I put them on for the first time with a new button. Then I feel something in the left pocket and lo and behold: The missing button! I have no idea what's the story behind it coming off and getting into that pocket is in the first place, but I bet it's an interesting one....