I was mistaken for a Muslim yesterday

Which really shouldn't be surprising, but it's the first time it's happened that someone actually said something. A very nice little old man came into the office, and I'm visible from the front counter. He said 'wa salaam alaykum', and I said 'hello', and the short conversation sort of went from there, and I did correct his mis-impression. I wasn't even dressed particularly hijabi-esque yesterday.