The Man from Earth is a 2007 American drama science fiction film written by Jerome Bixby and directed by Richard Schenkman. It stars David Lee Smith as John Oldman, the protagonist. The screenplay was conceived by Jerome Bixby in the early 1960s and completed on his deathbed in April 1998. Synopsis: A departing university professor claims to be a prehistoric caveman who has secretly survived for more than 14,000 years.

References:
https://en.wikipedia.org/wiki/The_Man_from_Earth