Earlier quoted context omitted.
Your mistake is trying to find logic in something Douglas Adams wrote. It makes no sense for alien spaceships to carry conkers. That's the joke, a small dig at people believing the local stuff they're used to is universal.
Don't take this the wrong way, but I don't think you understand Adams. He was incredibly logical. That was his genius: He would extrapolate on every topic to their logical conclusions - from computers to science to religion. When he was being absurdist, he was very clear about it. Like you said, he was writing about conkers as if it's just the same in the rest of the galaxy, which is definitely absurd. But in order t…
Oh, sure. But his writings weren't.
> But in order to ground that absurdity, the rest has to be normal.
Maybe we haven't read the same books ? I would not say that conkers are the only absurd element in the book (or even in the paragraph).