Mousse : noun Gas bubbles accumulated on the surface of a pressurized liquid.
To make mousse : have bad blood, worry, worry ...
Make mousse : make a scandal, a scandal.
Order a mousse : a beer.
A mousse ! : a beer.
Mousse : a glass of champagne.
Thin and silky pubic fleece.
The expression "Rolling stone does not amass moss": An adventurous life does not allow you to amass goods (or wealth).
On the pebbles (or stones) that have not moved for a long time, we find a beautiful green moss. On the other hand, on pebbles that move regularly, those moved by torrents, for example, there is no moss, because it does not have the opportunity to have time to settle there and spread there.
This ancient proverb from the XNUMXth century therefore encourages people to stay home-like, to focus on a very specific activity, in order to have chances of filling their wallet.
It also seems that "travel trains the youth".
If we mix these two proverbs, that would mean that young people who travel cannot enrich themselves other than intellectually.