What Sara Blakely Wished She Knew in Her 20s

It's not every day you meet a self-made billionaire, let alone the world's first female billionaire, and get her to share her secrets to success. Sara Blakely, the owner and creator of a product most women probably have in their wardrobe—Spanx!—is polished, smart, knows a thing or two about building a business, staying true to yourself, and setting your sights high. Here, she shares 10 important lessons she would tell her younger self.

1. Your own rear end is going to be your best asset.

"In business, you're going to hear the word 'no' a lot. The importance of trusting your self and your own rear end is what's going to keep you going. Recognize that failure or the word 'no' is not the end. It wasn't even something that registered for me.

When I started Spanx, I got my first really big order from Neiman Marcus. You get that big order and you think that that's when you've arrived, and that's when the hardest work happens. I went out and bought all my own products off the shelves and paid all my friends to go buy the Spanx products, because I was relying on myself to ensure success. I didn't even want to rely on the sales associates in the stores. This was my big break, so I took two years and stood in the department stores and sold Spanx myself, but I felt like, 'This is up to me to make sure it happens.'"

2. Brush up on your sales skills.

"Cold-call selling teaches you the most unbelievable life skills. It teaches you how to get your foot in the door or win somebody over in 30 seconds or less. It teaches you perseverance and to keep going, especially when people aren't necessarily kind or friendly to you. A lot of people ripped up my business card in my face.

Take a job cold-calling, even if for a short period of time. Do debate in high school or college if it's offered. Debate is such an amazing life skill—and I had no idea at the time that it was. It teaches you to see both sides of an issue and also to speak quickly on your feet and articulate yourself clearly."

3. Seek external inspiration.

"Take the time to learn how to think. Throughout school we spend so much time being taught things like geometry, trigonometry, algebra and history. All of that is really interesting and important, but nobody really teaches you how to think. So you have to take it upon yourself to be your own teacher, in order to reach your potential. The only place I could find that was helping to teach me how to think were motivational, inspirational CDs. It wasn't a course in school I could take.

When I started listening to Wayne Dyer at the age of 16 my whole world opened up. Life became bigger, richer, more important, and better. What you think about yourself is the most important of all. The visualization and manifesting ... I've been visualizing and manifesting things for myself long before The Secret book came out, and I owe that to Wayne Dyer. It actually became a joke in high school, because nobody wanted to ride home with me after a party. They would say,'Sara's going to make me listen to that crap.' Literally, people would be, like, 'Don't get trapped in Sara's car. She'll make you listen to this totally whackadoodle guy named Wayne Dyer.' Fast forward all these years, and I end up on the cover of Forbes and I got some pretty hilarious texts from some of those friends, saying, 'Damn. I should have listened to that stuff.'"

4. Spend time alone.

"When you spend time alone, that's when your gut really has a clear channel to you. It's so important to trust it. I think that trusting your gut is like a muscle. The more you do it, the stronger it gets. I recognized, just by asking myself some personal questions and also being quiet with myself, that I hear my gut the loudest when I'm driving in the car alone."

5. Failure is important.

"Every terrible thing that happens to you always has a hidden gift and is leading you to something greater. I actually started writing them in my notebook. I've been keeping a notebook since the start of Spanx, and I always have it with me. So I probably have about 20 notebooks on my shelf. I log and keep track of all the terrible things that happened to me, because it's almost become a game for me now. I like to see the gift and when it unfolds. It doesn't always come right away.

For me, I had always wanted to be a lawyer. I debated in high school and college. I took all the legal courses, and then failed the LSAT, because I'm a terrible test taker. I actually took a prep course and failed it a second time. At that point in my life, that was a pretty terrible thing, and I was devastated. It took about eight or seven years for the gift to reveal itself, but the gift was I was not meant to be a lawyer because Spanx was going to happen."

6. Ask yourself 'why?' daily.

"My obsession with the word 'why' did two things for me in my life. It caused Spanx to become invented, because I asked 'Why are pantyhose the way they are? Why are shapers the way they are? Do they need to be that way? Is there a better way?' That created product. Then it made me recognize and find my purpose, which was to help women. I'm very, very passionate about helping women, and that came as a result of continuing to ask myself, 'Why am I doing this? Why am I inspired to do this in this moment? What is this connected to?"

7. Be kind (and stop worrying about what other people think).

"Always be kind. Along the way, some people liked me; some people didn't. As long as I'm in check with my 'why' and my purpose, and I know that I have a good intention and I'm being kind, I've got to let go of all of that other worry."

8. Business doesn't have to be war.

"When I first started Spanx, I was at a cocktail party. A bunch of people had heard I had invented something and came up to me and said, "You know, Sara, business is war." I just didn't accept that and I didn't believe that. I believed that it could be different.

I've been focused on the customer, focused on delighting and surprising her, and making her life better, and haven't had any kind of a cutthroat attitude, such as 'other people have to be destroyed or demolished for me to succeed.' That was not my path."

9. Let go and delegate.

"When I was in my 20s, I took inventory of what I was good at, what I wasn't good at, and what I did and didn't enjoy. As soon as you can either afford to delegate what you don't like to do, do it. If somebody can do something 80 percent as good as you think you would have done it yourself, then you've got to let it go."

10. Don't overshare.

"When I first thought of Spanx, I didn't tell anybody for one year. Nobody told me not to share the idea with people. This was just a gut feeling that I had. After a year I told my friends and family, and I heard, 'Honey, this is such a good idea. Why hasn't it already been done?" and 'Even if it is a good idea, the big guys will just knock you off in six months, and then you've just spent your life savings on this.' If I'd heard those thoughts the first day I had the idea, I'd probably still be selling fax machines today."

And just when you think Sara can't be any wiser, she reminds us she is just a gal, like the rest of us. She was recently at the White House all day and said, as her final piece of advice to her younger self, "Keep comfortable. Always keep a pair of flats in your purse or near you. And, of course, have your Spanx on."