"Listen, three eyes," he said, "don't you try to outweird me, I get stranger things than you free with my breakfast cereal." - Douglas Adams

The lights were off so that his heads could avoid looking at each other because neither of them was currently a particular engaging sight, nor had they been since he had made the error of looking into his soul.
It had indeed been an error.
It had been late one night — of course.
It had been a difficult day — of course.
There had been soulful music playing on the ship's sound system — of course.
And he had, of course, been slightly drunk.
In other words, all the usual conditions that bring on a bout of soul searching had applied, but it had, nevertheless, clearly been an error.

If there's anything more important than my ego around, I want it caught and shot now.

"The mice were furious."
[...]
"Oh yes," said the old man mildly.
"Yes well so I expect were the dogs and cats and duckbilled platypuses, but..."
"Ah, but they hadn't paid for it you see, had they?"
"Look," said Arthur, "would it save you a lot of time if I just gave up and went mad now?"
[...]
"Earthman, the planet you lived on was commissioned, paid for, and run by mice. It was destroyed five minutes before the completion of the purpose for which it was built, and we've got to build another one."
Only one word registered with Arthur.
"Mice?" he said.
"Indeed Earthman."
"Look, sorry - are we talking about the little white furry things with the cheese fixation and women standing on tables screaming in early sixties sit coms?"
Slartibartfast coughed politely.
"[...] These creatures you call mice, you see, they are not quite as they appear. They are merely the protrusion into our dimension of vast hyperintelligent pandimensional beings. The whole business with the cheese and the squeaking is just a front."
The old man paused, and with a sympathetic frown continued.
"They've been experimenting on you, I'm afraid."