People like Oprah Winfrey and Steve Jobs are people who were College/University dropouts and still made it to where they are today. So, is education the key? The answer is no, not all the time. There has been people who do not have a College/University degree and have trouble finding jobs. If education was the key to success, that would mean that people around the world who do not have access to education would be incapable of being successful; which isn't true.
In other cases, education is key. If someone wanted to become a scientist, mathematician, etc. they would need to have a degree. A lot of people in businesses nowadays really depend on education, even if the person has has tons of experience in that field.
Therefore, it depends on what occupation you would be pursuing.