True caffeine addicts will appreciate the devotion of the 'Death Before Decaf' tank by Pyknic.
Some people just don't understand how crucial caffeine is to being a high-functioning human being -- or just a functioning human being, for that matter. Those same people probably won't understand your frustration when someone tells you there's only decaf left in the office ("but it tastes the same!"). To true java worshipers, drinking decaf is a betrayal worse than any other. They would rather surrender their own lives than succumb to the atrocity of sipping on a caffeine-free impostor.
If you, too, would rather cease to live than accept a decaffeinated drink, then this stubborn shirt is just right for you. All hail the coffee bean!