After working in coffee for awhile, and avidly consuming it for much longer...
I'd like to think that there is a correlation between the length of one's order at a coffee shop and one's level of maintenance. Surely the fact that one orders a double tall, non-fat, extra hot, half caf, sugar free, black and white mocha with a splenda and no whip says something about one as a person. Or at least one's relationship to Meg Ryan. Or maybe what's more telling is the frustration that happens when the drink is not made to such precision. (This amazing guy Ethan Nichtern calls this "latte suffering" - a "petty violence" we enact on the barista for making a drink incorrectly, but also on ourselves for allowing ourselves to care about a cup of coffee that much. But that's another discussion.)
I'd like to think that I'm above judging people by what they drink. But I'm just not. I realize this is influenced by the significant gendering of coffee, as recently noted in Bitch Magazine's "Wired" issue - hence why I love it when women order double cappuccinos or plain black dark roasts, or when men order blended, Frappucino-like drinks. Nonetheless, you have something powerful and complex in your cup, something that has shaped empire and culture and philosophy (see Mark Pendergrast's Uncommon Grounds). Enjoy the bite, the acidity, the finish. Stop messing it up with half a cup of cream and three packets of Equal.
I'd also like to think that people are, generally speaking, intelligent and at least capable of noticing a sign or two. This, however, has shown itself to be false. The signs that say "We'll get your coffee when you get off the phone," or "We are currently out of soy," or "Our credit card machine is down" never seem visible enough. Inevitably, customers order while carrying on about their latest breakup or hottest movie star, ask for soy, or try to pay with credit cards while the signs stare them in the face.
I could go on. Mind you, I don't mean to be an ignorant asshole. I just do this for a living, so give me (and a million other broke baristi/e) a break and toss a dollar in the tip jar. Get off the phone. Put everyone out of their latte-suffering.
Or I'll keep making your drinks decaf without telling you.