I got to meet Roland fryer a couple years ago, and he had an interesting background. While he went to Penn for grad school, he had offers from pretty much every top department. He went to a small college in Texas where he got in with a football scholarship.
After I think a year or two, he quit football and decided to study econ. He has admitted that he could barely read when he got into college. While he's extremely gifted with mathematics, I couldn't imagine that he got much farther than real analysis and diff eq given the time he had and the size of his school. At my undergrad, they only offer real analysis once a year, and upper level classes once every 2 years.
IN the end though, Roland is now a tenured faculty at Harvard under the age of 30, and the youngest person ever to be invited into the society of fellows