You'll Say I Already Am

I saw something on my dining table.  Is that a piece broken off that owl figurine?  No, it's the wrong size and color. I picked it up.  It was a pistachio nut, without a shell.

How did it get there?  I have no pistachios in the house, nor any mixed nuts.  Did a ghost drop it?  Did I carry it in on the bottom of something else, and it just happened to fall off on the table?  Did I bring a squirrel inside with my flowerpots and patio furniture?  No, it couldn't be that, or else my apartment would look like the Griswold's living room.  (Or does that happen only if a dog is involved?)

I'm not imagining it.  I don't think. Maybe I'm going nuts.