Two scenes sit side by side here: a party full of laughter, and a girl lying awake in bed. The poem begins with the partygoers, who seem carefree, and then turns to the one person who isn't there. The repeated question, "Did nobody ever think...", sounds half like a complaint and half like a plea. It suggests nobody noticed her absence, and that stings more than being left out on purpose.
The speaker, or the girl she describes, believed she was a friend and now sees otherwise. Her pain quickly turns inward. Instead of blaming the others, she calls herself stupid and "crap" and wonders why anyone would ever bother with her. The quotation marks around "friends" show her bitterness and doubt.
The mood is lonely and quietly sad. The short, plain lines mimic her thoughts circling "around and around," and the last line, which repeats the opening idea of being left out, leaves her stuck with that single fact.