In the Harbor/Loss and Gain

When I compare What I have lost with what I have gained, What I have missed with what attained, Little room do I find for pride.

I am aware How many days have been idly spent; How like an arrow the good intent Has fallen short or been turned aside.

But who shall dare To measure loss and gain in this wise? Defeat may be victory in disguise; The lowest ebb is the turn of the tide.