According to Carl Sagan, this old (pagan, I believe) phrase was used to ward off evil fairies.
Although I suppose that there are those around me who sincerely believe in evil fairies, I’ve never known of them. And if a person does believe in evil fairies, I would be surprised if they knew the supposed magic behind this word.
All my life, I have considered the mythical concept of a fairy—like the tooth fairy or the fairy god mother—as benevolent. But, apparently, in olden times, they were mostly regarded as evil.
I’ve talked of this subject of gesundheit before in my The Renaissance of Exercise. I revisit it here to tell a short and true story.
About 25 years ago, I was standing in line at the service desk of a Comp-USA store. I sneezed and the young woman standing immediately in front of me said, “Bless you.” This phrase, of course, is more common to my ear, but is said in the same context as “gesundheit.”
The woman—who was apparenly of late high-school age—sheepishly smiled when I responded, “Do you know the meaning of that phrase?”
With positive attitude and honesty she admitted, “No.”
I asked, “Do you believe in evil fairies?”
Again—now smiling and giggling—she answered, “No.”
I then asked, “Are you going to go through life saying things of which you know not the meaning?”
By now, she was truly embarrassed but still giggling as I explained the meaning and origin.
Obviously, I was having great fun at her expense, but she was a great sport about the exchange. With another personality, the exchange might have gone badly.
I am glad I came to know you better.