Our lovely educational system

It was a fairly slow day, so I thought I'd have some fun with the cute blonde teenager behind the counter at a local fast food eatery. I placed my order, and in that order I requested a small drink. The girl responded with, "We don't have small. We just have medium, large, and super." Let the fun begin...

Me: "No small?"
Her: "No. Just medium, large, and super."
Me: "Well, isn't a medium drink really just a small drink, then?"
Her: "No, sir. A medium is a medium-sized drink."
Me: "If you have a medium, then by its very definition, medium means middle, meaning that there is a small and a large."
Her: "We don't have small..."
Me: "Not what I said. But, don't you agree that if you have just two sizes, then the larger size would be 'large,' and the smaller size would be 'small?'"
Her: "Yes." (Fortunately, nobody else was in line during this time).
Me: "So, if you have a large and a small, and something is sized between those two, then that size would be 'medium?'"
Her: "Umm, yeah...?"
Me: "So if you have a 'small, medium, and large,' and you remove the small, then the medium would then be the smaller size, so the medium would now be the small. Correct?"
Her: "Yes, but we don't have small-sized drinks."
Me: "Yes, you do. Your medium is a small. Your super should be the large."
Her: "But all we have is medium, large, and super."
Me: "What's the smallest sized drink you have?"
Her: "Medium."
Me: "Doesn't that make it the 'small?'"
Her: "Huh?"

We could have done this all day. Interestingly, as I was walking out, chuckling, I saw and thought about introducing the kid-size. After all, wouldn't the kid size be small?