For decades, billionaire investor Ray Dalio has rubbed elbows with some of the most successful people in the world. Along the way, he’s learned a thing or two — including a habit that the “who’s who” (as he calls them) are just better at than the average person.

“By and large,” Dalio tells CNBC Make It, the most successful people “are really much better” at knowing their weaknesses, he says.

In fact, Dalio, who currently has a net worth of $20.3 billion, believes the fastest path to success starts with knowing your weaknesses: “because if you don’t know your weaknesses, you can’t get around them,” he says.

So how do you figure out your weaknesses?

Dalio says daily feedback from those around you, like your boss and colleagues, is a good first step. You can also notice patterns in the mistakes you make.

And while most people have several weaknesses, it’s important to figure out your “one big challenge,” which is the weakness that is the biggest obstacle to getting what you want, says Dalio.

“For almost everybody, there’s one big impediment that keeps coming up,” he says.

Even Dalio has such weaknesses — for instance, he says he struggles with giving feedback well, “and not appearing to the recipient as being brutal with them.” He says he’s also often accused of “rambling or not being clear.”

Dalio writes his weaknesses down and posts them where he can see them daily so he is reminded of what he needs to work on.

Once you figure out your big weakness, talk to others about it to collect more information and find ways to turn it into a strength.

An easy approach is to find people who are more expert in that area, whether that’s a colleague a coach or a friend.

“You don’t have to know everything,” Dalio says. “You just need to work with people who are strong where you are weak.”

Since Dalio, who turns 72 on Sunday, stepped down as co-CEO of Bridgewater Associates in 2017 (he is now co-chairman and co-chief investment officer), he says he has been focused on helping others succeed through Principles, a people management software company he founded.

Last month Principles announced the Dot Collector Zoom app launch, a tool that allows real-time feedback during video meetings. Dalio says the app can help people get daily feedback while working from home.

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