The author of the two sentences "Chang'e should regret stealing the elixir, the blue sea and blue sky every night" expands his imagination. He thought of the moon from the Milky Way and the morning stars, from the moon to the fairy in the moon, and then to the loneliness of Chang'e after flying to the moon. Combined with the situation that he was alone in a room, he naturally regretted stealing medicine and flying to the moon. Although this is an imaginary word, it is reasonable. The whole poem expresses the loneliness and desolation, which of course reflects the poet's lonely life experience.