Success is more than being born with genius or having a lot of luck. No one accomplishes success by themselves. There really is no "self-made man/woman."
By looking at examples of "exceptional cases" we can learn lessons about "success." There are certain circumstances around successful people - culture, generation, year/month of birth, cultural background, lucky breaks in their lives, people who are around them, where they are from, etc. You only need to be "smart enough" and the rest is luck and hard work.