Regardless of how we define it, success can feel like a fleeting and often elusive target.

It takes confidence, passion, and drive to reach a level of success and then do what's necessary to sustain it.

We've collected wisdom from 14 prominent CEOs and entrepreneurs who have seen drastic ups and downs throughout their careers.

Their advice is as appropriate for someone just starting out as for an industry veteran.

Steve Jobs, Apple cofounder and late CEO

 Steve Jobs
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Steve Wozniak, Apple co-founder

 Steve Wozniak
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Jack Ma, Alibaba Group founder and chairman

 Jack Ma
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Marissa Mayer, Yahoo CEO

 Marissa Mayer
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Mark Cuban, serial entrepreneur and 'Shark Tank' investor

 Mark Cuban
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Barbara Corcoran, Corcoran Group co-founder and 'Shark Tank' investor

 Barbara Corcoran
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Warren Buffett, Berkshire Hathaway CEO

 Warren Buffett
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Jack Dorsey, Twitter co-founder and CEO/Square founder and CEO

 Jack Dorsey
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Richard Branson, Virgin Group founder and chairman

 Richard Branson
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Mark Zuckerberg, Facebook co-founder and CEO

 Mark Zuckerberg
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Aaron Levie, Box cofounder and CEO

 Aaron Levie
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Lori Greiner, serial entrepreneur and 'Shark Tank' investor

 Lori Greiner
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Marc Andreessen, serial entrepreneur and Andreessen Horowitz partner

 Marc Andreessen
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Michael Dell, founder and CEO of Dell Technologies

 Michael Dell
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