I have purchased, last weekend, Paul Hoffman's book The Man Who Only Loved Numbers. This is a biography of the great and equally eccentric number theorist of all times Paul Érdös.
The book has been published in 1998, two years after the death of Érdös in Warsaw. The first 25% of Hoffman's book is interesting and entertaining at the same time. It tell the story of a man who devoted his whole life to Mathematics, who travelled from country to country carrying all his belongings in a briefcase and a bag.