How useless it is to be worried

One of my team mates asked me today if I was nervous/worried about the board meeting tomorrow. My answer was "no". She didn't ask why, but here is my logic:

I am worried all my work time about how to increase performance, except during board meetings.

Because during board meetings I can't do much about performance. BEFORE and AFTER it, then I am always worried about performance. I can only do it when I am outside of the board room, working in the trenches. During board meetings I only accept what we did or did not accomplish, no reason to be worried about it - it's purely the result of our work and some amount of luck or lack of luck.