There was a time when it was usual for all snails to leave their mark, all left their long iridescent trail. Nowadays, however, it is very strange to find one that has left a mark, most are doomed to die without anyone knowing anything about their ways.
How did this come to happen? There is no clear answer, no exact date. Most likely it was a series of things piled one on top of the other. It all started a long time ago, when the empire had only begun to form. Snails became suddenly cumbered with toils, they didn’t have time anymore to make the strange substance of which their trail was made. All this was a very slow process, so no one care to notice while it was happening.
The empire grew bigger and bigger. The few snails which still left a mark behind were forbidden of doing so; some of them were forced to undo their way, to pick-up their trail and return home. We know the destiny of every snail is to return home, but for those who left a trail this destiny came before its time.
The empire continued to grow and one day all snails had to walk with their house on their backs, like humans walk with death. But in the beginning it was not so, snails walked around freely and left their mark, and they always knew the way back home. Today, after so much prohibition from such a big empire, there aren’t any snails left to leave a trail: they’ve lost their way back because they don’t have a place to return, because they don’t possess that strange substance with which they left their mark. Besides, they’ve forgotten everything about it.