The fireplace

It is said that the large number of fireflies in the region dates back to a time when the factory furnaces were all still in operation. They came from all over the world, drawn by the glowing red silhouettes of the factory chimneys.
Fireflies know they are bright, and have always been blinded by the illusion of being guides to humans. So, although they merely follow the movements of the workers' hands, they imagine that those hands actually spend their time following them around as they light the way.
The men find this story a little far-fetched, but they pretend to believe it anyway. Maybe because they have also been attracted to tales, however insignificant, that shed a little light on their lives.