Picture it, Sicily, 1922 I go to check the mail - our mail is kept in one of those big community lockboxes with a different box for everyone on the cul-de-sac, plus an outgoing mail slot, and a parcel box that comes with it's own specific key that you use for it. The mailperson places this key in your own mailbox whenever you have a parcel to retrieve.
And then freaked out when I took the parcels out and noticed my funko pop Wonder Woman keychain dangling from the door instead of the little USPS keychain.
So now my key is stuck in the parcel box, the parcel box key is with me, and there is a RIDICULOUS NOTE detailing the events of how I get there taped to the parcel box, with me asking the postperson for help in switching our keys back.