Who would write such a note?

jouest thought this was worth mentioning said

If a pun falls in the woods and no one is there to hear it, does it elicit a groan?

A note that was written, but not left behind. A calling card, undropped. Angry email draft, unsent.

You get the idea.

What do you think, though? Who would jot a note, but then (presumably) walk off with it?