“Whilst something is unknown, it could be anything. It could be the worst thing ever and usually when something starts to happen. You realise it’s not so bad.”

Source: The Lonely Dead (2004), Ch. 20

Source: Unleash the Night

Source: Flora & Ulysses (2013), Chapter Twelve: The Forces of Evil, p. 39

"Cat in an Empty Apartment"
Poems New and Collected (1998), The End and the Beginning (1993)
Context: Something doesn't start
at its usual time.
Something doesn't happen
as it should.
Someone was always, always here,
then suddenly disappeared
and stubbornly stays disappeared.

Theism and humanism
Context: Everything that happened, good or bad, would subtract something from the lessening store of useful energy, till a time arrived when nothing could happen any more, and the universe, frozen into eternal repose, would for ever be as if it were not. /.../ The physical course of nature does not merely fail to indicate design, it seems loudly to proclaim its absence.

The Open Mind interview (1985)
Context: When things get bad enough, then something happens to correct the course. And it's for that reason that I speak about evolution as an error-making and an error-correcting process. And if we can be ever so much better — ever so much slightly better — at error correcting than at error making, then we'll make it.

Source: A Little Princess

Source: The Collected Stories of Arthur C. Clarke