"[Dresden] was all right," said Billy. "Everything is all right, and everybody has to do exactly what he does. I learned that on Tralfamadore." (9.22.10)
Billy has found a way to make everything that has happened in his life seem OK: faith in Tralfamadore. What else has he tried to assuage the pain? Christianity (as a chaplain's assistant), money (he's making bank as an optometrist), and family (he marries a girl he doesn't like that much because he feels he needs to). But when all else fails, Billy goes for Tralfamadore.