This song is about being with someone but having a sick feeling of being alone.
The person Li describes in this song is somewhat selfish. Their relationship has no solid ground, so even though they’re together, she feels like she’s alone. This leads her to think about the future of the relationship and tries to figure out what to do: leave her “lover” and be alone or stay with him and be lonely.

The title of the song and the whole lyrical context suggests that she chose to leave her lover and finally accepted that it is better to be alone than to be lonely with someone else.