Once called a producer to say he was walking from Texas to Oklahoma "looking at birds".
Wrote an early draft of Dirty Harry (1971).
He is independently wealthy from oil money and does not rely on film making for a living. He simply makes movies out of love for them.
He grew up on a farm and worked as a farmhand before studying philosophy at Harvard. After graduating he went to Magdalen College, Oxford as a Rhodes Scholar but left before finishing his thesis (on Martin Heidegger) after a disagreement with his advisor. He moved back to the United States and taught philosophy at M.I.T. while freelancing as a journalist.
The last press interview he gave was in 1973.