...when you don't think to check the date on the milk before pouring. My morning coffee ritual consists of pouring my mug at least half full of milk, adding a bit of sugar, nuking it, and only then topping up w/ coffee. I definitely wasn't awake this morning because it wasn't until I got to that last step that I noticed the consistency of my skim milk was more that of buttermilk. Bleah!!! Thank goodness I'd just bought a fresh gallon of milk, so I still had milk for coffee.