He who does not gain loses.
More French Proverbs:
Love makes the time pass.French
When you are well off keep as you are.
French
One finds little ingratitude so long as one is in a position to grant favors.
French
Who is born a chicken loves scratching.
French
He that spends more than he is worth spins a rope for his own neck.
French
Whoever rubs himself with garlic will not smell of cloves.
French