Marc Andreessen has an interesting (if long) post titled
Age and the Entrepreneur in which he reviews Dean Simonton’s research into the links between age and creativity in various endeavors. Having done a number of startups over the years I read with keen interest to see what he concluded for my future. Alas, the posting was just part 1, so I’ll need to wait until his next post.

IMHO most posts on this oft discussed topic miss the most important point. Entrepreneurship is a state of mind. It’s a personality type. Marc quotes Dr Simonton on this point:

” . . . those who generate the most contributions at the end of a career also tend to have begun their careers at earlier ages . . . ”

In other words, the traits which make someone an entrepreneur should express themselves early, and that those talents don’t necesarily peak in their youth.