Why do Bao Zhao's poems all have "Dai"? Can you explain why?

Dai means "for", writing for others. Just like an experience you Xingzhe told me, let me write a poem for you. My name is Dai. But why is he like this?

Bao Zhao is different from Xie Lingyun and Yan Yanzhi who were born in the nobility. Faced with the depression of life and the threat of those in power, he dared not express his dissatisfaction in a big way, so he had to use "Dai".

He studied the form of folk Yuefu, expressed his repressed life experience, especially his seven words "It's difficult to do things", and expressed his resentment against the poor, with a strange, sharp and dangerous style.

Do you see it?