weierstrass and more: http://mathoverflow.net/questions/3591/mathematicians-who-were-late-learners-list http://mathoverflow.net/questions/3591/mathematicians-w

weierstrass and more: http://mathoverflow.net/questions/3591/mathematicians-who-were-late-learners-list http://mathoverflow.net/questions/3591/mathematicians-who-we... http://mathoverflow.net/questions/25630/major-mathematical-advances-past-age-fifty http://mathoverflow.net/questions/25630/major-mathematical-a...