Vonnegut initially struggled with his narrative approach in Slaughterhouse-Five. His war experience was so awful, and he had been so young, that a more literal and linear reconstruction eluded him. As he began to gather his ideas, he connected with a war buddy roughly twenty years after the fact: Bernard V. O’Hare. He and Vonnegut “were captured together during the war.”
Vonnegut, by his nature and vocation, needed to address what had happened to his generation of WWII vets.
The nicest veterans in Schenectady, I thought, the kindest and funniest ones, the ones who hated war the most, were the ones who really fought.
During their exchange at O’Hare’s home, Bernard’s wife, Mary, accused Vonnegut of wanting to retroactively recast her husband and himself. They had basically been raw youths at the time, and she believed he wanted to recast them as Men, with a capital ‘M,’ with the intent of glorifying combat, such as in the John Wayne movie The Longest Day (a conventional sort of media representation of war). Kurt Vonnegut Jr., the adult veteran, father, and writer, portrays himself as searching for a meaningful way to present the younger version of himself. His fictional persona, Billy Pilgrim, and his peers are blundering boys surviving on the sidelines of an historic atrocity.
In his earlier works, notably his first novel, Player Piano, Vonnegut had become known as a writer who augmented autobiographical elements with a science fiction filter with the modus operandi of questioning authority and the system. During the development of Slaughterhouse-Five, Vonnegut understood that his story was by nature so insane that it demanded an act of narrative schizophrenia to be set down. Shattering the narrative construct and "becoming unstuck in time" was his solution—a deflection of the unvarnished terror of that trauma.