若无其事本来是最狠的报复
[ruò wú qí shì bĕn lái shì zuì hĕn de bào fù]
'If pretending nothing happened is the fiercest revenge' suggests taking a cool, nonchalant attitude as the ultimate response to wrongdoing. Instead of showing that one has been hurt, acting indifferently is viewed as the most powerful form of retaliation.