"Scintillation", 1970 by Michael F. Nyiri

We live our lives with certainty,
From day in to day out.
We can have a happy outlook,
As we travel a straight route.

As long as the sun is shining,
Our lives retain some grace,
And it is very seldom,
That something ruins the pace.

But lives do not pass without,
The cold, the bleak, the stark;
The thing that goes bump in the night,
And footsteps in the dark.