笨蛋不懂傻瓜的痛傻瓜不懂笨蛋的伤
[bèn dàn bù dŏng shă guā de tòng shă guā bù dŏng bèn dàn de shāng]
This sentence literally means 'fool doesn't understand the pain of idiot, and idiot doesn't know the heartbreaks of fool'. A deep statement implying different persons have suffered unique pains, which are hard to fully understand by those without experiencing it themselves.