In 3,000 BC, a Sumerian drill sergeant was tasked with training a ragged platoon of illiterate teenagers to defend their homeland. When his new charges faltered, he gave a speech to motivate them. In the last 5,000 years, that same speech has been given millions of times in every human language. It goes something like this:

Somewhere, a True Believer is training to kill you. He is training with minimal food or water, in austere conditions, training day and night. The only thing clean on him is his weapon and he made his own web gear. He doesn’t worry about what workout to do – his ruck weighs what it weighs, his runs end when the enemy stops chasing him. This True Believer is not concerned about ‘how hard it is’; he knows either he wins or dies. He doesn’t go home at 17:00, he is home. He knows only The Cause. Still want to quit?

Drill instructors are masters at motivation. The entirety of military training consists of instructing recruits to do a series of seemingly impossible tasks. As training continues, the tasks become more difficult. Eventually, the recruit realizes that he can do just about anything that doesn’t instantly kill him, and he becomes a soldier.

Never been to basic training? No problem. Find things that motivate you, books, slogans, movies, whatever. Remind yourself of who you are and where you are going.

In the Special Forces Qualification Course, the cadre is careful not to encourage or discourage. There are men who are great performers, but they require an audience. Without external incentives, they become disoriented and unmotivated. A Green Beret must be internally validated. He must be able to work as the only American for extended periods with no supervision. There is no drill sergeant to yell at him, no peers to encourage him.

In a joint environment, a Green Beret may work for a conventional chain of command that does not understand his methods or logic. Armed with nothing more than absolute confidence in himself and his training, the Green Beret must sometimes fight the enemy, coax reluctant allies, and co-opt a skeptical chain of command all at the same time. How can he do this? Because he knows that he is the best hope of stopping the True Believer from attacking his home and family. He can’t fail and he can’t quit.

Find your mission. Know why you are important. Be your own drill sergeant.