Once, I heard an old man say that there is a kind of bird that flies to many places in its life, no matter how far it flies or how tired it is. In the last season of their lives, they almost want to fly back to the place where they were born. However, even if some birds can no longer fly, they stand on the branches they depend on for survival, silently watching their companions fly away from their foreign lands and return to their homeland. Until their bodies are frozen and can never come back. Whenever the night falls, there will always be waves of low bird calls in the sky where the birds fly over. When you listen carefully, the sound seems to come from the depths of your soul, "I want to go home... I want to go home..."