"Without" describes emotional numbness from the inside. The speaker, addressed as "you," feels nothing at moments that should hit hard, and the poem treats that blankness as strange and a little unsettling. A loud party only adds noise, not joy, so the speaker withdraws into the one place that feels big and quiet enough: their own head. But it is also an empty place, and the poem never pretends it's comforting.
The mood is flat, tired, and quietly sad. Short lines and the repeated pauses ("And yet," "So sad," "Maybe not") make the voice sound worn down. Near the end, we learn the numbness may be protection. The speaker has "taken some hits," and "no one came." Other people scold them for being cold, though they do care, as the last stanza insists. They just feel caught in a snare, wanting to feel and unable to. The ending leaves that frustration unresolved.