To remain calm in stressful situations, Navy SEALS use a breathing technique called ‘box breathing’.
Bill Shepherd, first US Navy SEAL that became a NASA Astronaut and first commander of the ISS, was asked what he does best in his astronaut candidate interview. He answered: “Kill people with a knife”
Chris Kyle, known as the most lethal sniper in United States history, lost his life at 38 when he tried to help Eddie Ray Routh, a veteran suffering with PTSD, by taking him to a gun range. Instead, Routh turned his gun on Kyle and killed him.