Go to Bed Mad
We're taught to "never go to bed mad" with our spouses. But the reality is that we often think better in the morning. Many times, we won't even remember what we were mad about.
When you're running a business, you can expect to deal with problems - a lot of problems. You're everyone's go-to person for problems.
If there are issues with an employee, you worry about how it will affect your client relationships, for example. It's easy to work yourself up about things - grind away at the issues and try to resolve everything in your mind. It's a recipe for frustration.
It's many times better to let things go... resolve what you can through immediate communication, but then try to only care about the things that you can change. Worrying doesn't help resolve anything, and it's many times better to sleep on things.
I've learned to compartmentalize things in a way, to just do everything I can every day, but then let the things that I can't change drop. Or at least let them rest until another day.
It's many times good advice to "go to bed mad" at your spouse. To say, "Hey, I love you, but we're both tired, let's go to bed" - to address things fresh in the morning.
Same goes with business - stewing in worry makes everything worse. Do what you can each day, and let the rest go. Resolve what you can quickly, and then move on to other things where you can make an impact.
Trust that each morning everything will again be new.