Secret of success from life of successful people

When we study the success stories of many billionaires or renowned personalities in the world, we come to disclose a great success obtaining secret, and that is
                  'Keep on trying'
The scientists who cloned Dolly the Sheep, succeed after 276 attempts, before they were successful in cloning.
(Source:HowStuffWorks "How Cloning Works"
If we study the success history of Jack Ma Alibaba founder and a billionaire, we come to know that he failed at 30 jobs at first before founding his billionaire company.
 
If we study the invention of bulb by Edison, we come to know that
He failed 999 times before inventing this light giving invention to our lives.
 
So simple lessons of success are

          Never lose heart

                   and

          Keep on trying

You will be definitely successful in the end if you work consistently.