There is a long-held belief among academics that truly creative intellectual work can only be performed by the young. (For example, Hardy wrote, “I do not know of an instance of a major mathematical advance initiated by a man past fifty.”) I'll be honest - as I get older it's pretty depressing to ponder the possibility that my best, most innovative and productive years (intellectually speaking) may be behind me. But this terrific article in the New Yorker gives me hope - it's the story of Yitang Zhang, a mathematician who solved a 150 year old problem at the age of 51.
There may still be hope for me yet! :)