Short term memory loss

So, I'm sitting in a place called coffee roasters. I waited about 10 minutes to order my iced mocha. I paid and walked back to my table and continued on my work. After about 10 minutes, I heard no swishing from the machine, or ice being ripped from the cooler. Nothing. I look over and the guy is standing behind the counter reading a magazine. Now, explain to me how a person forgets an order that quickly? The place was not packed, except for a man working on his laptop in the back. How could he forget that easily? I find that to be something that a gerry would do, but a 20 something. Anyway, I walked up to ask about my order and right he asked me "what can I get started for you?" I told him that I already paid and was waiting for my drink. He then looked at me as if I were lying then realized about that iced mocha drink order lingering in the back of his mind. He made my drink and gave me a large for the delay. Funny.