Simplify the following text for a Grade 6 native English-speaking person.
Original: The plot focuses on John Oldman , a departing teacher who claims to be a Cro-Magnon ( or Magdalenian caveman ) who has somehow survived for over 14,000 years .
Simplified: All of the film takes place in a small house and its porch , where Oldman tells his friends that he is a 14,000 year old Cro-Magnon caveman .