"Space," it says, "is big. Really big. You just won't believe how vastly, hugely, mindbogglingly big it is. I mean, you may think it's a long way dow… - Douglas Adams

"Sir Isaac Newton, renowned inventor of the milled-edge coin and the catflap!" "The what?" said Richard.
"The catflap! A device of the utmost cunning, perspicuity and invention. It is a door within a door, you see, a ..."
"Yes," said Richard, "there was also the small matter of gravity."
"Gravity," said Dirk with a slightly dismissive shrug, "yes, there was that as well, I suppose. Though that, of course, was merely a discovery. It was there to be discovered." …
"You see?" he said dropping his cigarette butt, "They even keep it on at weekends. Someone was bound to notice sooner or later. But the catflap … ah, there is a very different matter. Invention, pure creative invention. It is a door within a door, you see."
"Is this when you're wearing the helmet?" "Especially when I'm wearing the helmet!"

The Total Perspective Vortex derives its picture of the whole Universe on the principle of extrapolated matter analyses.
To explain — since every piece of matter in the Universe is in some way affected by every other piece of matter in the Universe, it is in theory possible to extrapolate the whole of creation — every sun, every planet, their orbits, their composition and their economic and social history from, say, one small piece of fairy cake.
The man who invented the Total Perspective Vortex did so basically in order to annoy his wife.
Trin Tragula — for that was his name — was a dreamer, a thinker, a speculative philosopher or, as his wife would have it, an idiot.
And she would nag him incessantly about the utterly inordinate amount of time he spent staring out into space, or mulling over the mechanics of safety pins, or doing spectrographic analyses of pieces of fairy cake.
“Have some sense of proportion!” she would say, sometimes as often as thirty-eight times in a single day.
And so he built the Total Perspective Vortex — just to show her.
And into one end he plugged the whole of reality as extrapolated from a piece of fairy cake, and into the other end he plugged his wife: so that when he turned it on she saw in one instant the whole infinity of creation and herself in relation to it.
To Trin Tragula’s horror, the shock completely annihilated her brain; but to his satisfaction he realized that he had proved conclusively that if life is going to exist in a Universe of this size, then the one thing it cannot afford to have is a sense of proportion.

He has personality problems beyond the dreams of analysts.