Analysis

In Slaughter House 5, Kurt Vonnegut has an interesting view of time. He describes it as seeing all time at once, instead of seeing it as a linear fashion like we do. The main character Billy Pilgrim, can travel backwards and forwards through his life, and always knows what is going to happen. Kurt Vonnegut describes people as "Great millipedes with babies legs at one end and old people's legs at the other". This means when he looks at someone, he see's where they have been, and where they are going, not just them how they are at that particular point in time.
If this view of time was real were real, you would never be surpriosed, you would keep repeating the same moments of your life over and over. It would get annoying after a while, life will have lost it's meaning, and you would have no way to stop it. I think he has put this in the book because this is what he believes happens after we die, we may not be aware of it, but it is what is happening to every human being.
In the book, I think billy Pilgrim is not really jumping through time, I think he is just remembering parts of his life he has already lived, like the war, and making up the things he hasn't yet lived, like his death. This could be a way of dealing with the mental images jumping around his head from the war. He could be trying to find something that makes everything he saw okay. This is when he makes up the tralfamadorians, and turns it into his philosphy, his way of life.
I do not believe he is lying when he tells people about the tralfamadorians, I think he is simply so wrapped up in this philosophy is simply so wrapped up in this philosophy that he truly believes it is real. Like Schizophrenia maybe?
I believe that he is mentally ill in result of the war and the things he witnessed, and now he is seeing things and believing things that aren't really there.