Vaughan's poem is about the small lies we use to get through hard times. The opening line, "Everything's fine," is quickly undercut by the next: we say it "when we know it's a lie." From there the speaker moves through familiar comforting phrases like "It's gonna be ok" and "It won't be like this forever," the kind of thing we are taught to say to a stranger who is visibly upset, or to ourselves.
The mood is tired and quietly sad rather than angry. The speaker seems worn down by waiting for change that never arrives, since things have been bad "for so long" that a better time feels like a distant memory. The ending is the saddest part. The speaker compares that hope to childhood, when believing "everything was great" came naturally and needed no effort. Now the words are repeated out of habit, and the poem's plain, conversational tone makes that loss feel honest and close to home.