Two-Things!
Diane had a circumstance/event category for two-things. Perhaps it was midwesterner jargon? I struggled with the notion. The question was how is that different from coincidence? Her answer was, "Simple! For example, the clock shows 11:11. That's a two-thing!" To me, 11:11 might be a two-thing but, seeing it makes it a three-thing, or a coincidence. I rest my case.
The following are examples of real two things:
•   Two bricks shy of a load.
•   Two feathers shy of a duck.
•   Two cards shy of a deck.
•   Two slices shy of a loaf.
•   Two bottles shy of a case.
•   Two bits shy of a byte.
•   Two bits shy of a dollar.
•   Two degrees shy of North.
•   Two fries short of a Happy Meal.
•   Two protesters shy of a parade.
•   Two geese shy of a gaggle.
•   Two bananas shy of a bunch.
•   Two trees shy of a forest.
•   "Two Notes Shy of an Octave."
•   Two sandwiches short of a picnic.
•   Two degrees shy of boiling.
•   Once bitten, twice shy.
•   (Destination) to Chi.
•   (Fencing) Touche!
This is all to, too, two much!
Related Links:

Bird List
"Diane"

"Diane's Ducks"

"Diane's Lilacs"

"Partner"