You're in Seattle, right?
I don't stick to one Starbucks. I've gone to various Starbuckses and there's quite a few different ones I've been to that I had to explain what an Affagato shot is. Off the top of my head, I recall Southcenter, Bellevue, and Lynnwood had this experience. It's also happened a couple times in Downtown Seattle. Heck, even the Pike Place Market one didn't know and I said, "Ask one of your coworkers." Boy, was I shocked when that happened at PPM of all places. They did make the most amazing looking Frappucino I've ever seen, though.