The Mystery of Washing Dishes

Even though I have an automatic dishwasher, I still wash some dishes in the sink. You know, the fragile ones, or those that are too big, for example.
Or, when the dishwasher is fully loaded and you've got a few things that didn't fit, and you want to have a clean counter top so you wash the extras by hand.
This is rather mundane stuff, to be sure--but have you ever noticed the mysterious event that takes place after you let out the dishwater?
As every good homemaker knows and does, you look around to see if there are any left to wash before you let out the drain: perhaps a glass that's hiding behind something on another counter, a fork that has fallen on the floor under the table, you know...stragglers.
I look, and look again, yep, I've got 'em all.
I let out the water.

And here is when the mysterious event takes place.
Another dish shows up. Every time.
It is down-right uncanny...