Gauss Reading

Quote: "Early in this period-perhaps at the age of 14 or 15- he discovered the prime number theorem, which was finally proved in 1896 after great efforts by many mathematicians."

Question: How can someone so young figure out a theorem that many mathematicians couldn't figure out?

Comment: This quote interested me because Gauss figured out a theorem that mathematicians had a hard time figuring out and they were about half (or more) his age, and they probably had more experience than he did. But yet he figured that out before them and they finally had proved his theorem many years after he had.