Perhaps none more so than Alexander Grothendieck exemplifies the mathematician and since 1991 lived as a recluse in Andorra. However since the body of work and his contribution to mathematics, particularly, category theory and topology has been almost legendary he retains a great mystery about him.
In order to understand Groethendieck and possibly the mind of the mathematician a series of biographies of Groethendieck are being written by Leila Schneps. The current draft and extracts can be found on her pages about this work.
I'll quote a paragraph from Chapter 1 of Volume II, that gives a flavour of Groethendieck's work and approach to mathematics:
Taken altogether, Grothendieck’s body of work is perceived as an immense tour de force, an accomplishment of gigantic scope, and also extremely difficult both as research and for the reader, due to the effort necessary to come to a familiar understanding of the highly abstract objects or points of view that he systematically adopts as generalizations of the classical ones. All agree that the thousands of pages of his writings and those of his school, and the dozens and hundreds of new results and new proofs of old results stand as a testimony to the formidable nature of the task.
This is truly a work at a scale a magnitude more detailed than, say Simon Singh's fascinating documentation about Wiles' work and proof of Fermat's Last Theorem. Suffice to say, I look forward to reading it. Maybe Simon Singh should make a documentary about Groethendieck?
** I credit Andrew Wiles with inspiring me to study for my PhD back in 1995