Jordan Ellenberg (JSE on MO) wrote a nice article after Perelman announced his solution of the Poincaré conjecture:
"Is Math a Young Man's Game? No. Not every mathematician is washed up at 30." Slate, May 2003. (article link.)
The article ends with this:
"It's only in the presence of both conditions—deduction and inspiration, long experience and youthful audacity—that new math gets made, as it was made by Perelman, and as it was made on the day Poincaré wrote down his conjecture. He was 50 years old."