I don't know how you can put yourself in the "born great" category. Birth itself is the world's grandest lottery. It determines pretty much everything about your life, from the way you look, your life expectancy, your language, your first religion, to the opportunities you get in life. Once you are born you have to accept your luck and join in the race.
I also don't know how you can have greatness thrust on you. Not everyone can become the Pope and the chance of planning your way into becoming one is extremely slim. No one should base his life on positive coincidences. You shouldn't have life plans built on expecting people to favour you. There will always be people who get uncommonly lucky, or have too many positive coincidences in their lives. They even rise to become the president of a country by lots of unusual favourable events. They have greatness thrust on them. In science, they are regarded as the outliers. You can't replicate their success by following their footsteps.
However, if you have a well used intelligence (even if it is an average intelligence, you just need to put it to use) and work extremely hard and have a great self confidence (one that makes you invincible to failure) and take on risks (rather than settle for a "me too" life) you are working your way to greatness. You will end up becoming the best you there can ever be. You will have a tough life (at first), then you will get used to it and finally you will become someone of immense value.
You need the combination of those 4. But the most important of them all is the insane hard work. Intelligence is just to help you achieve more with less. Great self confidence is to make the journey easier for you as you encounter difficulties and setbacks. High risk appetite is to make you go for a big goal. But it is hard work than gets any significant thing done. Your success will depend more on your work ethic than you IQ. And like it's been said, "You 'I can' is always more important than you 'IQ'".
The business owners we envy today are not exceptionally intelligent or have a greater self confidence than everyone else. They simply took on a big goal (starting a business) and put in the insane hard work (and resources) required. The modern conveniences you enjoy wouldn't exist if someone didn't put an insane hard work into converting an academic theory to practical physical gadgets.
You need to work hard at something big and audacious, then put in all the intelligence you can lay your hands on (your intelligence and other people's) and have a failure conquering self esteem. Then you'll be setting yourself up for greatness.