Alexander Grothendieck was one of 20th century's most brilliant mathematicians. His work is considered revolutionary.
Yeah, he was a little out there. How did you guess?
Grothendieck was born in Germany to a Russian Jewish revolutionary and a local goyishe woman. The two considered marriage too bourgeois, so Alexander was saddled with his mother's last name, as opposed to his father's rather Jewy Schapiro. That helped him survive World War II, but not before he decided to run away to kill Hitler. He was about 12 years old.
We'll skip over Grothendieck's mathematical career, for it is clearly too complex for us. There was dabbing outside of mathematics as well: failed attempts to start communes, dreams that proved to him that G-d exists, a promise of a "new age" (to be ushered on in 1996) and thousands upon thousands of pages of unpublished work (ramblings?).
In 1990, Grothendieck disappeared from public life and moved to the Pyrenees. He there lived in isolation until his death.
So, yeah, you guessed right...