How can I tell? Someone made popcorn. My boss hates the smell of microwave popcorn so when she's out of the office staff take advantage of it and make popcorn. The smell permeates the whole office. I don't mind it. It makes me laugh.
It reminds me of my old job too. We shared the bottom floor of our building with a Youth Service group and they used to make popcorn every Friday. The smell would waft through the cooridor and all the way into our office. Good times.