Two short lines carry a whole story of loss. The speaker says they promised someone the stars, a grand, almost impossible gift, the kind of thing people say when they want to show how much they would give. But the other person "took the moon" instead. The moon is closer and more real than the stars, and taking it suggests she reached for something the speaker never offered, or took more than was meant to be given.
The speaker's tone feels quietly stunned, maybe a little rueful. There is no anger spelled out, just a plain statement of what happened. The closing line, "all I am worth," is set apart and reads like a confession: what was taken was everything the speaker had to offer, or perhaps the speaker's whole sense of self-worth. The title, "Dissection," hints at being cut open and examined, which fits that feeling of exposure. The mood is bare, sad, and vulnerable, and its brevity makes the hurt land harder.