Tony Robbins believes emotions are the most important factors that determine success.

"Emotions are everything," Robbins said. "Success without fulfillment is the ultimate failure."

The best-selling author and life coach sat down in conversation with Tom Bilyeu, the co-founder and president of Quest Nutrition, a fast-growing protein bar company valued at a reported $900 million. As part of the brand's weekly Inside Quest video series, Bilyeu sits down with a successful business icon to find out what makes him or her tick, and to glean any tips the person can offer founders. 

Robbins, who wrote the book Money: Master the Game (Simon & Schuster, 2014), has managed 12 businesses at once, and coached more than 50 million people in his career to date. His clients have included Carl Icahn, Bill Clinton, and Oprah Winfrey.

Surprisingly, he flags that achievement won't bring you happiness or success. What's important is recognizing your core values, and adopting a lifestyle that aligns with those values. "The decisions we make control us much more than the conditions we meet," he said.

Here are a few takeaways from the interview, which you can watch in full here: 

1. Focus on building a business that adds value to the world, not dollars in your bank account. 

Robbins had recalled an aha! moment after meeting Norman Vincent Peale, the late minister and author of The Power of Positive Thinking. 

He paraphrased a mantra that he learned from him: "You feel so filled up when what you do adds so much value to people's lives that it lights them up. You can't compare that with money," he said. "But if you run your business right, and you add that much value, you will do well financially."

2. There is a "model" that will help you reach success. You just have to look for it. 

In coaching others to manage their lives, money, and companies, Robbins relies on a series of "models." These can apply to any endeavor, from shooting a pistol to landing a happy marriage. 

"Once you figure out the pathway to power, once you figure out the pattern of effectiveness, the model, you can teach that model to other people," he said. "Whether it be money, or relationship, or your body, those models are there." 

3. There's power in preparation.

Before doing an interview, Robbins says he gives himself at least 18 hours to prepare. The extra time gives him a boost of confidence, allowing him to spitball during the meeting, and ask the questions that nobody else has asked.

As he prosaically puts it: "If you keep putting unbelievable quality in, when its time for you to cash that spiritual, emotional, physical, financial, or business check, it ain't gonna bounce, because you've been making deposits, and you've got plenty to give."

4. Become an expert in your industry. 

Robbins laments that society today is largely focused on acquiring a limited knowledge of a lot of things, rather than a ton of knowledge around a specific craft. Focus is the key factor that turns startups into large, successful companies.

"Most people are running for the sugar, the next thing that feels good, instead of getting past what doesn't feel good, and getting to where you own something," he said.

Simply put, the key to success is weathering the knocks, and coming out stronger for them.