Humans invented trains, because it satisfies the primal hunan desire to sit in the guts of a large worm, as it moves through the dirt at high speed.

according to the phenomena of galactic carcinisation, all nebulae will eventually become the crab nebula

It's kind of messed up, when you think about it. Biologically speaking, even the very nicest and most well-meaning person has their heart in the left place.