From Ralph Waldo Emerson:
Finish every day and be done with it. You have done what you could. Some blunders and some absurdities no doubt crept in; forget them as soon as you can. Tomorrow is a new day; begin it well and serenely with too high a spirit to be encumbered with your old nonsense. This day is all that is good and fair. It is too dear, with its hopes and invitations to waste a moment on the yesterdays.
A good reminder that goes with my previous post. Living in the past does us no good except to harm ourselves. Living in each moment, cherishing each day as it comes is all that we have.