I don't think you should always stay calm in a tense situation, because you might not ever confront the problem. Maybe it's better to actually let yourself be tense - and find a solution.
I learned about the strength you can get from a close family life. I learned to keep going, even in bad times. I learned not to despair, even when my world was falling apart. I learned that there are no free lunches. And I learned the value of hard work.