"Pietra che rotola non fa muschio"
"A rolling stone never gathers moss"

There are various theories about the origin of this proverb, which has been known since ancient Rome. This proverb refers to what is well known about mosses and lichens: that they are slow-growing organisms that do not thrive if disturbed. A sure way to prevent a colony of moss from growing on a stone is to move it. In the traditional interpretation, our protagonist moves little until the moss covers his path, whilst the more modern understanding suggests that success depends on action and a sort of metaphorical transience with a contradictory reading.