David Goggins begins his story by telling us that life can be very hard, but we can grow stronger than the hard times. He says he was once a scared little boy who felt weak and alone. He grew up in a small house that was often filled with loud fights and fear. His dad made the family work late at night in an ice-skating rink the family owned, so young David hardly slept. When he went to school, he was tired, hungry, and behind in his classes. Other kids teased him because he could not read well and because his skin was dark. He felt stupid and slow, and he thought nothing good would ever happen for him. Yet, even then, a small voice inside told him not to give up.As he grew older, the troubles did not stop. David watched his mother leave his father so they could escape the beatings at home. They moved to a new town, but money was short and hope was smaller. David also found out he had a hole in his heart and serious asthma, which made running hard. In high school he was heavy from eating cheap food, and he felt sorry for himself. He worked nights spraying for bugs in fast-food places, then went to school tired. One day he looked in the mirror and did not like the boy who stared back. He called this the “Accountability Mirror.” He wrote simple notes on sticky paper and put them on the glass: “Fix your speech problem.” “Drop the weight.” “Study for the test.” He learned that the only person who could change his life was the one in that mirror.After barely finishing school, David signed up for the Air Force. He passed the first part of training, but when he had to swim long distances he panicked and quit. He felt shame for leaving, so he drifted for a while and ate doughnuts for comfort. One night he saw a TV show about Navy SEALs. The men on the screen looked fearless and free. David decided he would become one, even though he weighed almost three hundred pounds. A kind Navy recruiter told him he had only three months to lose over one hundred pounds or he could not even try out. David stopped feeling sorry for himself. He ran in old shoes until his feet bled, rode a bike in his garage while sweat pooled on the floor, and learned simple math and words each night so he could pass the entry test. In exactly three months he met the weight goal and the test score.SEAL training was many weeks of cold water, sand, and almost no sleep. It is famous for “Hell Week,” where most people quit. David went through three separate Hell Weeks because he got hurt twice but refused to stay down. He broke bones in his legs and kept running by stuffing his socks with cardboard. He taped his shins and took no pain pills. He told himself that when the body thinks it is done, it has really used only forty percent of its power. He called this the “40-Percent Rule.” Each time he hit a wall, he reminded himself that more strength was still inside, and he pushed again.When his time as a SEAL slowed, David looked for new tests. He decided to run the toughest races on Earth—ultramarathons of one hundred miles or more. His first big race was a one-hundred-mile loop run on a broken foot. By the seventieth mile his body was shaking, but he wrote every past pain in his mind into what he named the “Cookie Jar.” Each memory was a cookie: being beaten as a kid, failing in school, three Hell Weeks. When he felt weak, he reached into the Cookie Jar and pulled out a memory to remind himself he had survived worse. He finished the race. Later he broke the world record for most pull-ups in twenty-four hours after failing the attempt twice. He also served in Iraq, hunted bad guys, and helped rescue friends under fire.