If David can do it, anyone can. Or if you are unsure what to do, ask yourself: "What would Goggins do?" I love that thought. He devised some brilliant little tools to help him when it gets tough. Every time something gets tough and I want to quit, I remind myself: you are just at 40% of your abilities. This insight alone has helped me so many times in just this one year since I read the book. It also made me realize I always quitted when things got hard. Well, not anymore.