Goggins recalls being in peak physical condition for the Air Force’s Pararescue school but dropping out over fear of the water exercises. To qualify as a Navy SEAL, he had to develop his “Mental Lab”: a space where he transformed insecurities and excuses into fuel for improvement. He needed to lose over 100 pounds in under three months for SEAL training but prioritized mental fitness over physical conditioning because “[y]ou don’t need six-pack abs when your mind is steel-plated” (69). He designed endurance workouts to build mental strength.

In his Lab, he developed his “savage” alter-ego, someone who can overcome any obstacle. Soon after, he went through three SEAL Hell Weeks and trained with broken bones. He refers to the weak, scared, former version of himself as “David,” whom he contrasts with the savage side of his psyche. The author argues that everyone can access a Mental Lab for this type of self-reinvention.

Six weeks after his heart scare, however, Goggins realizes he has lost some of his savage mindset. He receives an email asking him to run that summer’s 100-mile Leadville Trail race to raise money for charity, but he does not respond immediately.