The speaker is lonely in a way that's easy to miss from the outside. The poem opens with numbers: twenty-four hours in a day, more than a million people in the world. These figures sound like a promise. With that much time and that many people, surely someone would have noticed something was wrong.
But the last two lines turn that idea around. Nobody has asked the simple question, "are you okay?" The speaker isn't asking for a grand rescue, just for someone to check in. The plainness of the question makes the absence hurt more.
The mood is quiet, tired, and a little bitter, though the speaker doesn't shout. Even the spacing around the punctuation, with its little gaps before commas and question marks, makes the voice feel flat and hesitant, like someone saying this out loud for the first time. The poem suggests that being surrounded by people can still feel like being alone.