Motivation is going to let you down," says retired Navy Seal Jocko Willink, "Discipline will stay by your side."

Retired Navy Seals like Willink lead exceptional lives long after they have left the battlefield. By cultivating discipline in the terrible battlefield of war, they're able to navigate with ease through the battlefield of life with the one skill that really matters. Self-control.

Your brain is always leading you toward a goal

Every moment that you are awake, you carry a goal of some kind in your head. At the front of the brain, sits your brain's CEO, in your prefrontal cortex. It programs your behavior to get you to that goal.

While your short-term goals navigate your day-to-day existence, your long-term goals grow your character and propagate you toward success.

Your brain's CEO has to engage its self-regulatory skills to battle distractions as you keep your eye on the goal. Decaying motivation is one of the distractors it must battle with.

Motivation isn't always easy

If the pleasure of something in your surrounding tempts you more than the pleasure of reaching your goal, or if temporary distress during the process eclipses the reward of the goal at the end, your motivation will dwindle and you will give up.

On the battlefield, and in life, you can't be a puppet to the strings of motivation. If low motivation threatens your mission, you need to be able to override it.

Jocko points out that on a battlefield, "If you get too hungry sometimes you're not motivated. If you get too tired sometimes you're not motivated." But if you let your receding motivation guide your behavior, you're putting your life in danger.

How do you keep going when there's no motivation there?

The only thing that can override an absence of motivation is self-control.

Willink says,"It's about discipline. Holding the course. Knowing what you have to do. And making it happen."

This is what your brain's CEO, the prefrontal cortex does. Unswayed by distractors, it holds the course, it knows what it has to do and it makes it happen.

If you rely on motivation, you won't always reach your goal, but self-control will always get you there.

How do you improve self-control?

Some theories suggest self-control is like a muscle. The more you train it, the stronger it gets. How do you train it? You force yourself to do something that needs self-control and discipline to complete, as often as you can, ideally every day.

According to Willink, "figure out what sucks the most and do that thing the most."

Your menu is endless. It can include holding uncomfortable yoga poses, or practicing tightrope walking, or doing the hundred push-ups you planned to do after getting out of bed every morning, even if your shoulders are aching with exhaustion.

Controlling attention is a key part of self-control. Seasoned focused-attention meditators are able to block out all thoughts and focus on one thing with less effort than non-meditators. Their muscles of self-control become better with regular training.

What happens if you master self-control?

You become master of your universe.

"He who controls others may be powerful, but he who has mastered himself is mightier still." ? Lao Tzu