Wisdom, as they define it, is the quality of having experience, knowledge and good judgment. In short, it is being wise. People's personal experiences are the only proof needed for the fact that wise people are mostly successful. Therefore, it is indeed worth a lot when someone who has reached the peak of their success shares their wisdom. Take a look at some of them:

Michael Dell, Founder of Dell "One of the things I see in new businesses is that they are often looking for perfection. I think this is a big mistake. I think you ought to be looking for experiments -quick experiments. It's ok to have little failures. What you want to do is to learn as much as you can very quickly and try things. When we were a small business, we would go out and do all sorts of things to find what would work. When we find what works, we go out and do it a hundred or thousand more times. We still do that today as a large company."

George Clooney, Actor "If there is something you want to do, then just get on with it. Give it a shot. Failing is not the issue, it's not trying that I find is the issue."

Mohammad Ali, Professional Boxer "He took a few cups of love. He took one tablespoon of patience. One teaspoon of generosity, one pint of kindness. He took one quart of laughter, one pinch of concern. And then, he mixed willingness with happiness. He added lots of faith, and he stirred it up well. Then he spread it over a span of a lifetime and he served it to each and every deserving person he met."

Michael Jordan, Professional Basketball and Baseball Player and Investor "The things that I've done in my life - I've taken a chance of succeeding or failing at it. But I've taken that chance. I will not let the opportunity of failure stop me from doing something that I choose and enjoy doing."

Arianna Huffington, Founder of Huffington Post "The way to a more productive, more inspired, more joyful life is to get enough sleep."

Jeff Bezos, Founder and CEO of Amazon "Take pride in your decisions and hard work but not in your gifts. Celebrate your gifs, enjoy them, but don't take pride in them. Take pride in your decisions and hard work."

Sheryl Sandberg, COO of Facebook "Go where there is growth because where there is fast growth creates opportunity."

Richard Branson, Founder of Virgin Group "Focus on the people. Find the best people to run the company. Make sure they are properly incentivized, properly motivated, and give them freedom to go ahead and make good things."

Steve Jobs, Founder of Apple "Don't settle. Your work is going to fill a large part of your life, and the only way to be truly satisfied is to do what you believe is great work, and the only way to do great work is to love what you do. If you haven't found it yet, keep looking. Don't settle. As with all matters of the heart, you'll know when you find it. And, like any great relationship, it just gets better and better as the years roll on. So keep looking until you find it. Don't settle."

Eric Schmidt, Former Google CEO "Everybody needs a coach. Every famous athlete, every famous performer has somebody who is a coach. Somebody who can watch what they are doing at them Give them perspective. The one thing that people are never good at is seeing themselves as others see them. A coach really, really helps."