Sarah's poem is a short, raw statement of grief. The speaker has lost someone, and the loss has left them emptied out. They describe it almost physically: the remaining happiness was "sucked out," as if the loss pulled it from them like air from a room. The word "remaining" suggests that some happiness was already fading, and this final loss took whatever was left.
The speaker feels hopeless, and the title, "how can i be happy," turns into a question the poem never answers. The closing lines make it sound less like a question and more like a conviction: nobody could be happy when this person is gone. The world itself "went cold," so the speaker's inner state spreads outward to everything around them.
The mood is bare and heavy. There is no fancy imagery or rhyme, just short lines and plain words, which makes the sadness feel honest and unguarded, like someone speaking quietly right after the loss.