The key is to keep calm:

Research shows training very hard and imagining the worst that could happen are two powerful techniques for promoting calm.

Samurais trained relentlessly. They strongly believed you should always "be prepared" (they were like the deadliest Boy Scouts imaginable.)

Research shows that preparation reduces fear because when things get tense, you don't have to think.

More on that: 

http://theweek.com/article/index/256464/the-samurai-secret-to-always-being-at-your-best

They also were resolved to die at any moment, in battle or at the simple request of their lord...

Now that's preparation.