How Growing Up With Nothing Equipped Me to Run a Billion-Dollar CompanySheldon Yellen started life on the mean streets of Detroit. There, he learned four life-changing lessons.

You might not think a little kid living in a rough area of Detroit has a direct line to a billion-dollar company. Typically, he doesn't. But hecanfight and work his way there if he wants it enough.

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I should know. Raised by a single mom and the eldest of four boys, I learned how to work hard from an early age. I got my first job at 11 and gave all my earnings to my mom. I learned how to work selflessly -- with no expectation of handouts or rewards -- and to appreciate every opportunity I was given.

Eventually, I got a chance in the property restoration business because my wife's family owned the company. My in-laws gave me a job at the bottom of the ladder. And, initially, my colleagues didn't respect me; they thought I'd only gotten there through my new connections. This made me hungry to work my way up and prove I was there for a reason.

And that's just what I did. I used the fierce work ethic I'd learned as a kid to turn my bottom-rung position into CEO ofBelfor, a disaster recovery company. You too can learn from the lessons I lived:

1. Never spend money without thinking.

When I had my first job at a burger joint, I looked up to the servers. I'd watch how they served the customers, so I could emulate them when I got the chance.

One day, the restaurant was slammed and we were short a server. The owner said, "Hey boy, you're going to wait your first table right now." That day, I made my first tip: one precious dollar. Excited, I cashed it and used a dime on the pay phone to call my mom. As soon as I told her my news, she hung up. Later, when she came to pick me up, I learned she didn't want me wasting 10 percent of my tip on a phone call; she'd taught me the value of a dollar better than that.

It was my first business lesson. That day, I learned that if you look after dimes, you look after dollars. Don't take any of it for granted, even when the numbers get really big.

2. Keep your ears to the ground.

Scraping and saving through my early life gave me a variety of experiences to draw from in my career. I've been a disc jockey, a vending-machine stocker, a ticker seller and -- at an elite athletic club -- a shoe shiner. I'd see men play racquetball and golf in the middle of the day and wonder how they could afford to live like that. I tried to listen to their stories to see how they did it.

I learned the arts of listening and watching. I realized I could learn from everybody around me, and as a result, every situation became an opportunity.

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3. Keep your field knowledge fresh.

As a leader and supporter of my team today, it's my responsibility to learn as much as I can about the industry and climate we're in. Keep your field knowledge fresh and your trade terms topped up. Don't ask your colleagues to do anything you've never done yourself. Employees will give their respect and hard work to a leader who's getting his hands dirty alongside them.

4. Remember your roots.

According to a recent study by Catalyst,humilityis one of the most important factors for leadership -- it makes people from different backgrounds feel included. When those surveyed witnessed acts of humility in their leaders -- such as admitting mistakes and learning from criticism -- they were more likely to feel connected to their teammates.

In my early days, I worked in an office of 19 people. I made everyone in that office handwritten birthday cards to show my appreciation. To this day, I still do that for my colleagues – all 7,000 Belfor people around the world!

From supporting my family at an early age to earning dollar tips at a burger joint, I learned how to support a team of thousands. And I have the tough streets of Detroit and my even tougher mom to thank for that.

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