Mood: The mood of the video appears to be melancholic and introspective, with a sense of despair and sadness. The theme seems to revolve around heartbreak, loss, or regret, as hinted by the title 'I KNOW' and the somber expression on the person's face.

Environment: The setting of the video seems to be indoors, possibly in a room with a window in the background, given the soft, diffused light. The simplicity of the background and the focus on the person's emotional state suggest that the video may be more focused on the emotional journey of the protagonist rather than on elaborate settings or plotlines.