What is the loneliest ancient poem you have ever read? Why does it last forever after supper?

Ten years of life and death are two boundless, disapproving and unforgettable. -Su Shi's "Jiangchengzi"

The courtyard is lonely and the spring scenery is dying; Pear flower falls, close the door. -Liu's "Spring Complaint"

Raise my cup, I invite the bright moon, which brings me its shadow and makes us three people. The moon doesn't know how to drink, but the shadow in front of it is behind. -Li Bai's "Drinking the Bright Moon Alone".

The west wind withered the green trees last night. A person in a tall building can see the end of the world. -Yan Shu's "The Recent Flowers"