Themes
Finish each day and be done with it. You have done what you could. Some blunders and absurdities no doubt crept in; forget them as soon as you can. Tomorrow is a new day; begin it well and serenely.
— Ralph Waldo Emerson

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
Each day should be closed out and let go once effort has been given. The speaker accepts that some mistakes and foolish moments will have slipped in, and advises forgetting them quickly. The next morning is a fresh start, to be entered well and with calm rather than dragging yesterday's errors along.
Context reviewed