I'm outside and my mother is inside. What is a poem?

Homesickness. Homesickness is a modern poem written by Yu Guangzhong, a famous patriotic poet, in 1972. In the poem, I am outside, my mother is inside, and homesickness is a shallow strait. I am here and the mainland is there. The whole poem embodies the poet Yu Guangzhong's good wish for the early reunification of the Chinese nation.