Billy accepts the Tralfamadorian advice to look at life’s nice moments as much as possible. He still does not control his time travel, but he takes comfort in the foreknowledge he gains from it. For example, when Valencia declares that she will lose weight for Billy, he assures her that he likes her the way she is. Billy actually thinks Valencia is ugly, but he knows from his time travels that his marriage to her will be comfortable.
Billy’s revelations about Tralfamadore lead us to question his sanity. It seems possible that Tralfamadore is something that he merely imagines, especially since he begins reading Kilgore Trout’s science fiction at a stage in which he feels he is losing whatever grip he has on reality. He is already unable to live fully in the present and unable to control his movements backward and forward through time. Science fiction helps him and Rosewater as they attempt to “reinvent themselves and reinvent their universe.” Perhaps Billy, unable to change the fact that he cannot live his life normally after the war, salvages his sanity by inventing a new understanding of the nature of time. The Tralfamadorians, who are strongly reminiscent of some of Trout’s creations, conveniently explain how the whole thing works and serve as a model for coping in a four-dimensional universe. People who invent new understandings of the nature of time are seldom considered sane, but in his own mind, Billy is at peace. Billy probably suffers from both disillusionment from the war and delusions. While the delusions may outweigh his disillusionment in terms of his mental well-being, they perhaps allow him to function, at least part of the time, in the normal working world.