The speaker describes a painful kind of loneliness: feeling invisible until something visible happens. The opening repeats "No one" again and again, like a door shutting, and the single word "No one" on its own line makes the emptiness feel complete. Then the poem turns. Once other people see the scars from self-harm, attention finally arrives, but the speaker doesn't trust it.
The speaker admits the cutting might have been a way to release inner pain, or a way to make someone care, and says it doesn't matter which. What matters is how people react. Old friends suddenly become "new friends," yet their comfort feels like pity, not real care. The last lines are the bitterest: the speaker feels seen as weak and pitiful, and sometimes as "a toy," something to use. The mood is raw, bitter and lonely, with the sense that being noticed is not the same as being understood.