We know that Tim Ferriss is a New York Times best-selling author. We know that he's an extraordinarily successful entrepreneur, and an investor. What many don't know about Tim Ferriss is that he has bi-polar depression and was moments away from committing suicide during his college years.

It was what could have been his final moments, when Ferriss began his journey of discovery. It led him from self-destruction to becoming a person who The New York Times listed among their most "Notable Angel Investors," and CNN proclaimed as "one of the planet's leading angel investors in technology."

In this TED Talk, Ferriss speaks of what he calls the superpower that saved his life: stoicism. The philosophy of stoicism, founded in Athens by Zeno of Citium in the early 3rd century BC, asserts that virtues (such as wisdom) should be based on behavior, rather than words. And that we don't control and cannot rely on external events, only ourselves and our responses.

The philosophy, according to Ferriss, has grown like wildfire in the top ranks of the NFL as a means of mental toughness training. There's a whole world out there, centered around the stoic personality.

"Think about it as an operating system for thriving in high-stress environments and making better decisions," says Ferriss. He suggests that you train to separate yourself from what you can control and what you cannot.

"We suffer more often in imagination than in reality."- Seneca the Younger, a famous stoic writer.

Ferriss developed an exercise that he calls "fear-setting," and he suggests you do quarterly, at least. Goal-setting is important, but without fear-setting you may never achieve your goals. Ferriss asserts that by visualizing your worse-case scenarios in detail you can overcome the paralysis caused by them.

Here are the five critical questions Ferriss asked himself, as he practiced his fear-setting. When complete, you should have many pages of questions and answers to help you focus solely on what you can control, rather than what you cannot.

1. "What if ...". Here you will define your fears; the worst things you imagine. Name 10 to 20 things.

2. "What can I do to prevent or decrease the likelihood of these things happening, even a little bit?" Answer this question for each of your "what ifs".

3. "If the worst-case scenario happens, what can I do to repair the problem, even a little bit, or who can I ask for help?"

4. "What might be the benefits of an attempt or partial success?

5. "What is the cost of inaction?" If you avoid this action or decision and others like it, what might your life look like in six months, one year, three years? (Emotionally, financially, physical, etc.)