The islands of Micronesia didn’t use last names until the concept was introduced by Westerners. A lot of folks from the island of Kosrae decided just to repeat their first names. There was once a photo in the government newsletter with the caption, “From left to right: Louey Louey, Asher Asher, and Jack J. Jack.” (We were afraid to ask what the J stood for.)
Louey Louey was my neighbor and so I had a few stories in which he featured. (The subduing of the coconut crab being one). After a few years living in Micronesia the repeated names sounded totally normal to me. It was only when people started giving me weird looks because I was talking matter-of-factly about Louey Louey that I remembered how strange that was.
ETA: The above is tangential, sorry. Modern occupational last names might include Programmer, Therapist, Controller, or Ciyeeo (CEO).