Anyone in an office workspace knows how infuriating it can be when someone takes your things. Sometimes the only thing getting you through the day is the thought of that sweet delicious sandwich sitting in the fridge. So, when that little thread of hope is the only thing keeping you together something so small can make you come unhinged. Of course, when this occurs over the course of several days it will REALLY start to get to you. It will prompt even the sanest of us into posting normally outrageous notes.
Basically, if you have the choice in life, don't be a Francis.