What feelings do nostalgic poems express?

Feel sorry for others, hurt yourself, and feel your own life experience; Nostalgia for the past hurts the present, sentimental about the rise and fall of history and so on.

Regret that others hurt themselves and regret their own life experience: The author cherishes the memory of the ancients. Generally speaking, the life experience and fate of the ancients are similar to those of the author, with the trigger point in the ancients and the foothold in himself.

Nostalgia hurts the present and makes people sad about the rise and fall of history: most ancient poets are poor scholars, and the idea of helping the poor makes them pay more attention to national politics and social life. Poets often express their concern, enthusiasm, dissatisfaction and vigilance about reality by writing historical sites and historical events.