Yesterday both Matthijs and I received chocolate letters from someone. There was no note revealing the sender. All we have to go on is the handwriting on the envelopes (which we do not recognize), the fact that Matthijs was addressed as 'Mister Kooijman' (Dhr. Kooijman) and only my first name was mentioned, the person had the money to spend 4 stamps on each envelope, and a short printed verse: "Ik toon je niet mijn ware gezicht, want ik weet dat je me dan beticht, van weer een slecht gedicht". Either the person guessed right or he/she knows I do not like Sinterklaas poems. And it's on purpose that the sender is not revealed. Also, there's two different brands of chocolate (Verkade and the Plus brand) and one was wrapped in Sinterklaas paper and the other in normal gift wrapping.

We went through the possibilities but didn't come to one fitting solution. This is aside from the handwriting. I know the handwriting of my family members, and it wasn't theirs or they took care to obfuscate it.

• My father and his new wife already gave us chocolate letters.
• My mother and her partner would just give it to us and probably not spend as much money on postal stamps. Plus they have something else on their mind at the moment.
• My grandmother from father's side doesn't have or know how to use a computer for the printed note. And she'd include and sign a little note.
• Grandparents from mother's side would probably be practical and send both letters in one package or give them to my mother to deliver to us. And they would not be mysterious about it.
• My work. Though they know both our first and last names, so why leave out parts? However, the separate sending could be part of a series of sendings and they did celebrate Sinterklaas yesterday.
Helena. She likes puzzles a lot and she does live some 30 minutes drive away from us. However, here also the question of why the names this way?
• Matthijs' mother and her partner already gave us letters.
• Matthijs' father and his new wife would have given the letters or would have send them in one package probably. And why be mysterious about it?
• A fellow larper. But why the names this way? And geez, if this is part of a series he/she must have lots of money for all the stamps.
• Someone from Musilon, but we/they already celebrated/planned Sinterklaas and they live near us so why the expensive postal stamps?
• Sinterklaas, maybe he does exist?
• Someone else entirely but I'm out of guesses.

The addressing of Matthijs as 'mister' and the leaving out of my last name might mean that the sender doesn't know (how to write) the missing names. Or they're on such a social level with us that they know me well and Matthijs less well. Or they value Matthijs a lot for something he's done and they only know my first name. Still, we live on the same address, why not send just one package?

The two separate packages might mean that it's part of a series. Some grunt work; writing and stamping envelopes, wrapping the letters and sending it all. In this case it might have escaped someone's attention that the addresses are the same. However, if the addresses came from a system, why are the names incomplete? The difference in wrapping could also point to serial work, they might have run out of Sinterklaas wrapping at the last letter.

All those discrepancies together might lead to the solution, or it might all be coincidence. With Pandora at least you can assume that everything in a puzzle has to mean something, in this case we can't assume anything which makes it harder to come to a conclusion.

Can someone give us a hint? A tiny one?