When Did I Become A Ma'am?

I was headed through the drive-thru tonight which I should NOT be doing since there is just about no fast food that is gluten-free, but I have a major deadline so I can rationalize anything right now and figured I can remove the bun from a burger, right? As I pulled up to the second window after paying my fare to the nice girl at the first window (BTW, when did fast food become so expensive? I thought that fast food was supposed to be cheap. . .) a young gentlemen in one of those nice polyester uniforms says to me, "Here is your drink. Did I give you a straw already, ma'am?" He handed my my piping hot bag of 1000mg of sodium and 50g of fat and I was quickly jostled out of my post-work haze certainly not offended but definitely wondering when did I cross over into the realm of ma'am?