Late at night, the speaker sits at home thinking about an ex who no longer speaks to her. She hopes he's okay, but the poem quickly shows how much she's still hurting. She looks back on how they met, both sick in the nurse's office, and how she ignored the rumors about him and fell for his smile. The early excitement of swapping numbers gives way to the plain statement, "I'm not happy anymore."
The heart of the poem is her mother's childhood advice that ribs protect the heart. The speaker twists it: ribs "break pretty easily" when a beautiful boy comes along. She also admits he never promised "always, forever," only "a long time," and that she was ashamed to be won over by sweet texts. The mood is raw and wistful, a mix of regret, embarrassment, and lingering love. The ending shows this most clearly. Even now, she wishes his new girlfriend will avoid the same trap, his brown eyes.