We all know the story of how Jeff Bezos quit his Wall Street finance software engineering job to start up Amazon.com in his garage way back in 1994. Since then, Amazon has rocketed to annual revenues of $136 billion, and Bezos -- with a net worth of more than $94 billion -- is currently the world's richest person.

What most of us don't know, however, is exactly what gave Jeff the confidence to make the decision he did -- to leave behind his corporate job and strike out on his own.

On November 4, Jeff Bezos was interviewed by his brother Mark at the ideas festival Summit LA17 event in Los Angeles. During the course of this interview, Jeff revealed to the audience the mind trick he used to make up his mind.

As Jeff considered whether to stick with his safe and relatively lucrative career on Wall Street, he stepped back from his day-to-day activities at work for a few days to imagine what it would be like to start his own company. But he didn't just imagine what it would be like a month or year into the future. That would not have given Jeff the answer he was looking for.

As Jeff explained to his brother Mark, "The best way to think about it was to project my life forward to age 80," and then take the path that "minimized my regrets." According to Jeff, when he applied this mind trick, the right decision became "immediately obvious." He chose to quit his Wall Street job and start an online bookstore -- Amazon.com -- which soon grew into something much, much bigger.

And if he failed? No worries. Said Jeff, "If it failed, I would be very proud when I was 80 that I tried."

So, what tough decision are you waiting to make about your future direction? If you want to improve the chances of making the right decision, take a page from Jeff Bezos's book and project your life forward to age 80. Then make the choice that will make you proudest that you tried.

If you do that, you just can't lose.