the author's continuous use of " So it goes". What is the purpose? Why the repetition?

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So it goes," and "And so on." These two sentences consistently saturate every chapter of Slaughterhouse Five, forcing the reader to tirelessly absorb these two uncomfortably short sentences, and placing them into their subconscious. After a while the reader begins to read these six syllables without thoroughly thinking about them; they slowly become a chant or a metered mantra, rather than two significant sentences. Through repetition, the process of reading this novel begins to induce déjà vu, silently and repeatedly cueing the reader to go back and wonder if he's read the same page twice, or is he witnessing two distinct events. The importance of repetition strikes harder when the reader acknowledges that Slaughterhouse Five was published in 1968, during the height of another war: The Vietnam War.

While the usage of "So it goes" and "And so on" induces dizziness in the reader's head, the long-standing effects of their repetition goes beyond simple déjà vu. The sentence "So it goes," occurring over a hundred times throughout the novel, places the reader is several awkward positions. First, this repetition forces the reader to wonder how does it really go. Often tagged at the end of a paragraph, "So it goes" acts as a way for Vonnegut to conclude a narrative related to death. Critic Thomas F. Marvin indicates that such a usage of this terse sentence forces the reader to interrupt.