“My trouble is insomnia. If I had always slept properly, I'd never have written a line.”

Source: The Goose Girl

Anathemas and Admirations (1987)

Introduction (p. viii)
The Wrecks of Time aka The Rituals of Infinity (1967)

E. Jane Whately (ed.), Life and Correspondence of Richard Whately, D.D. Late Archbishop of Dublin. Volume II (London: Longmans, Green, and Co., 1866), pp. 451-452
Attributed

Source: Space Chantey (1968), Ch. 5, on Polyphemia
Context: Roadstrum had always believed that he had troubles enough of his own. He seldom borrowed trouble, and never on usurious terms. He knew that it was a solid thing that sheep do not gather in taverns and drink beer, not even potato beer; that they do not sing, not even badly; that they do not tell stories. But a stranger can easily make trouble for himself on a strange world by challenging local customs.
"But I am the greet Roadstrum," he said, suddenly and loudly. "I am a great one for winning justice for the lowly, and I do not scare easily. I threw the great Atlas at the wrestle, and who else can say as much? I suffer from the heroic sickness every third day about nightfall, and I am not sure whether this is the third day or not. I say you are men and not sheep. I say: Arise and be men indeed!"
"It has been tried before," said Roadstrum's friend, the sheep, "and it didn't work."
"You have tried a revolt, and it failed?"
"No, no, another man tried to incite us to revolt, and failed."

And then two or three years ago, someone showed me a site, and half of it that said I wrote it, I didn't write. Recently, I saw one, and I didn't write any of it. What's disturbing is that with a few of these jokes, I wish I had thought of them. A giant amount of them, I'm embarrassed that people think I thought of them, because some are really bad.
[The Tenacity of the Cockroach: Conversations with Entertainment's Most Enduring Outsiders, Thompson, Steven, 2002, Three Rivers Press, 0609809911, September 9, 2012, http://www.avclub.com/articles/steven-wright,13796/]
Interviews

As quoted in The Power of Choice (2007) by Joyce Guccione, p. 49