Force of habit

From a little snippet of conversation that occurred in my living room just now as a friend was about to walk out the door:

Me: Cool sunglasses! (They were. She'd just put them on, and I don't recall ever having seen them before.)

Her: Thanks! (Pauses. Looks at me, eyes suddenly wide with realization.) Which I totally don't need to be wearing right now. Seeing as it's the middle of the night!

Me: Uh, yea! I was thinkin...