You know, I'm not entirely sure what it meant but I was thinking it had to do with Trout speaking in the narrator's father's voice. I assumed that the narrator was in fact Vonnegut, and coupled with the idea that Vonnegut would soon attempt suicide, I think he was regretting things about life or reminiscing about the innocence of youth. Vonnegut's mother committed suicide when he was in his 20s, and his father pretty much became reclusive until he died of lung cancer. I think it had to do with seeing too much; the destruction of the world, people becoming more and more "mechanized" in the actions and thoughts, and how lonely it is living in a world of "machines." Youth would bring ignorance to all of this and basically set Trout free, as it would Vonnegut from the suicide of his mother and the disintegration of his father's personality. That is of course all a huge stretch based on family history, but I always get the feeling that Vonnegut puts a lot of himself into his works.