Akin to this week's theme, here are some Italian adages. I know we've done something like this before; sorry if I repeat any.

A closed mouth catches no flies
Trouble rides a fast horse
When ill luck falls asleep, let none wake her
A new broom sweeps clean, but the old brush knows all the corners
Better give a penny then lend twenty
Give neither counsel nor salt till you are asked for it
If the patient dies, the doctor has killed him, but if he gets well, the saints have saved him

and one which is also common in English:

If a man deceives me once, shame on him; if he deceives me twice, shame on me