To summarize the summary of the summary: people are a problem.

So this is it," said Arthur, "We are going to die."
"Yes," said Ford, "except... no! Wait a minute!" He suddenly lunged across the chamber at something behind Arthur's line of vision. "What's this switch?" he cried.
"What? Where?" cried Arthur, twisting round.
"No, I was only fooling," said Ford, "we are going to die after all.

You cannot see what I see because you see what you see. You cannot know what I know because you know what you know. What I see and what I know cannot be added to what you see and what you know because they are not of the same kind. Neither can it replace what you see and what you know, because that would be to replace you yourself."

"Hang on, can I write this down?" said Arthur, excitedly fumbling in his pocket for a pencil.

Vogon poetry is of course, the third worst in the universe.
The second worst is that of the Azgoths of Kria. During a recitation by their poet master Grunthos the Flatulent of his poem "Ode to a Small Lump of Green Putty I Found in My Armpit One Midsummer Morning" four of his audience died of internal haemorrhaging and the president of the Mid-Galactic Arts Nobbling Council survived by gnawing one of his own legs off. Grunthos was reported to have been "disappointed" by the poem's reception, and was about to embark on a reading of his 12-book epic entitled "My Favourite Bathtime Gurgles" when his own major intestine, in a desperate attempt to save humanity, leapt straight up through his neck and throttled his brain.
The very worst poetry of all perished along with its creator, Paul Neil Milne Johnstone of Redbridge, in the destruction of the planet Earth. Vogon poetry is mild by comparison.

Why?' is always the most difficult question to answer. You know where you are when someone asks you 'What's the time?' or 'When was the battle of 1066?' or 'How do these seatbelts work that go tight when you slam the brakes on, Daddy?' The answers are easy and are, respectively, 'Seven-thirty in the evening,' 'Ten-fifteen in the morning,' and 'Don't ask stupid questions.

And so the Universe ended.