Is it that obvious?

I was in Starbucks, minding my own business, earnestly stirring sugar into my latte. When I began the stirring process, I was alone at the condiment counter and was not aware of anyone joining me in the interim. Suddenly a voice boomed, "Can you pass the chocolate when you get a chance?" I grabbed the chocolate and handed it to the guy without thinking, assuming the chocolate incident was now finished. But the guy kept talking, "I find it's better if I add the chocolate *now*." That forced me to look at him - pouring his coffee beverage from one cup into another, stopping halfway to add the chocolate. I felt inclined to reply, "that makes sense, the chocolate will mix better that way." The guy stopped dead in his tracks, mid-pour, looked at me and said "you're a scientist." He then looked me over *very* carefully, seemed to notice ...