Back in 1973, when I married my first wife, we went to Europe for our honeymoon. We flew Air Icelandic, which was the airline of choice in those days for students traveling to Europe on a budget. The plane made a "refueling" stop in Reykjavik, which I firmly believe is really an excuse to bring tourists to shop in their duty-free shop. In those days, Reykjavik didn't have jetways -- we disembarked down portable stairs, outdoors, and walked across the tarmac to the terminal. Our flight originated at JFK and most of the passengers were Noo Yawkahs. As we were walking to the terminal, a lot of the passengers were sniffing the air and asking what that funny smell was.
My bride and I agreed that we didn't smell anything strange. We finally figured out that what all those Noo Yawkahs were smelling was clean air -- probably the first time in their lives they had ever smelled such a thing.