I can't find the whole poem on the net - don't know what it's called - and I don't have a copy of One Train. But a longer excerpt, probably with the wrong line breaks because email tends to screw them up:

I thought about this moment from time to time
For eight or ten years. It seemed to me I should have done something at the time
To have used all that energy. Lovemaking is one way to use it and writing is another.
But that is probably human destiny and I am not going to go against it here.
Sometimes there are the persons and not the energy, sometimes the energy and not the persons.
When the gods give both, a man shouldn't complain.

Kenneth Koch