Navy Seal explains how losing your temper makes you weak:

Perfectly said. When you respond in anger, you have a tendency to stoop to their level. When you respond calmly, it lends credibility to your response.

Rehashing the same old Jocko stuff...

Newbies seals While sleeping a platoon of experienced seals drew a line of magic marker on their neck. Upon waking the commander said-if this were the enemy -you with the marks in your neck would never wake up