笑并非是快乐哭并非是伤悲
[xiào bìng fēi shì kuài lè kū bìng fēi shì shāng bēi]
Expressed as 'A Smile Isn't Necessarily Joy, Crying Isn't Only About Sadness', conveying deeper meanings that external expressions don't always correspond accurately to true emotions. One can smile when feeling distressed and weep for reasons not solely due to sadness.