It’s one of the best pieces of advice I ever heard. On the occasions when I remember to follow it, things tend to go much better.
There is a corollary bit that I’ve also picked up over the years: Don’t blame yourself.
Blame just doesn’t serve any good purpose. Ever. You can’t change the past. What’s done is done. Whether you did it to yourself or someone else did it. It doesn’t mean nobody’s accountable. It means not dwelling in it.
Instead of placing blame, take responsibility.
Take a deep breath. Learn what you can from the experience. And move on.