“Things without all remedy. Should be without regard. What’s done is done.”
—Lady Macbeth

Kathryn Schulz, author of Being Wrong: Adventures in the Margin of Error, delivers an excellent TED talk on embracing our regrets.

“The point isn’t to live without any regrets. The point is to not hate ourselves for having them. … Regret doesn’t remind us that we did badly. It reminds us that we can do better.”

Related:
What We Do When Someone Disagrees With Us
Being Wrong