Exhaustion

It sneaks up when you're unprepared
And pulls the rug from under,
Full knowing you would not have dared
To fight to save your thunder.

For, unlike fog, with cat-like feet,
Exhaustion isn't fleeting.
When age and too much action meet,
It could be self-defeating.

A younger soul than I might last
Until that fog has lifted,
But time's been moving much too fast;
The balance might have shifted.