A doctor who wrote much during the Islamic Golden Age. Known in Western sources as "Avicenna".

20 years old when he disappeared into the woods. 47 years old in 2013 when he was caught.

• He slept in an unheated tent, in an area which falls to -20 degrees in the winter.
• He had contact with a single person, once, a hiker in the 1990s.
• He never made a phone call
• He never drove a car
• He never spent money (1000+ burglaries provided food)
• He never sent an email or saw the Internet

When he was asked about Thoreau, Knight dismissed him with a single word "dilettante" (dabbler, amateur, nonprofessional).

At the very end of each of our visits, I'd always asked him the same question. An essential question: Why did he disappear? He never had a satisfying answer. "I don't have a reason." "I can't explain why." "Give me more time to think about it." "It's a mystery to me, too." Then he became annoyed "Why? That question bores me." But during our final visit, he was more reflective. Isn't everybody, he said, seeking the same thing in life? Aren't we all looking for contentment? He was never happy in his youth–not in high school, not with a job, not being around other people. Then he discovered his camp in the woods. "I found a place where I was content," he said. His own perfect spot. The only place in the world he felt at peace.

Read more: www.gq.com/story/the-last-true-hermit

Fourier series: circles on circles in planetary orbits. Hard to come up with!

Birthday: 27 April