Katie Foster's poem is about the gap between how someone appears and how they truly feel. The speaker presents a cheerful, easygoing face to everyone around them, someone who laughs, takes jokes and seems to cope. Underneath, they describe themselves as a frightened, lonely, angry child who cries constantly and has nowhere to hide.
The mask is the central image, and it changes as the poem goes on. At first it is a convincing disguise, but then it becomes "old and worn," cracked and already broken. The speaker has been holding it together by effort alone, and now their arms, and their will, are exhausted. Letting it fall feels less like a choice than a collapse.
The mood is heavy and quietly desperate. The short, repeated line "I wear a mask" works like a refrain that keeps pulling the reader back to the secret. The ending is the bleakest part: the speaker says they'd ask for help, but believes none exists. The misspelled "non" in the last line makes it feel raw and unpolished.