Archaeology is the anthropology of the past, and science fiction is the anthropology of the future.
Beyond that, I seem to be compelled to write science fiction, rather than fantasy or mysteries or some other genre more likely to climb onto bestseller lists even though I enjoy reading a wide variety of literature, both fiction and nonfiction.
Don't worry. You're safe now. You've got nothing left to steal.
Probably I chose immortality because mortality is a universal human obsession.
Fear of the unknown is a terrible fear.
Besides, wouldn't it be wonderful if no one ever had to worry about the random cruelty of fatal illness or the woes of old age attacking them or their loved ones?