Looking at other people's misfortunes and thinking about yourself is also very sad. Make an idiom.

Tang Bangxi 'an

Pity: pity, sympathy. Metaphor is mutual sympathy because of the same experience or pain.

Zhao Hanye's Biography of the Harmony between Wu and Yue in the Spring and Autumn Period: "I don't know the song on the river?" Help each other in the same boat. "

~, write an elegy on the river. ("Nan Liu's Theory of Forgiveness")