bad brain day
A day when nothing anyone says to you makes sense, nothing you say makes sense to anyone else (including yourself), following directions proves problematic and items which should be readily locatable cannot be found (or are found only after much searching on top of one's head).
I knew it was going to be a bad brain day when I finally located my keys in the drawer where I always keep them, my glasses on top of my head, and remembered only after entering the now empty garage that my wife had earlier mentioned that it was her yoga day, which meant she was taking the car.