红尘事是非谁能辩
[hóng chén shì shì fēi shéi néng biàn]
This means 'In worldly matters, who can distinguish right from wrong?' It reflects the feeling that in the complex and often chaotic world, it's hard to discern truth and falsehood or to judge what is right and what is wrong, suggesting some disillusionment with societal norms.