Maybe this wasn’t really trolling, since it wasn’t mean? I was rushing up to the apartment to drop off groceries when I heard a woman and a man speaking Mandarin. I can speak it pretty decently, so I decided to use that as a chance to practice. When the woman held the elevator door for me, I said 谢谢 (Xiexie, meaning, “Thanks,” obviously). I had the tones right, and she seemed shocked. She asked the guy in Chinese, “Did that guy just say 谢谢??” The guy replied, “不是吧,” which was something along the lines of “Probably not.” I kept quiet (halfway out of a momentary shyness, halfway out of curiosity), and that was the end of it. Although it’s pretty cool to observe people’s reaction when they don’t expect you to speak a language when you do, I do prefer meeting random people that way.