American sci-fi: America is technologically, morally, physically, and intellectually superior. And the answer to all ills is more science.

Lazarus Long? IIRC he’s also his own parents due to time travel shenanigans. During his early adulthood, he gets a one night stand pregnant and never sees her again. A couple hundred years later he transitions to a woman, for reasons, goes back in time, gets pregnant from a one night stand with a drifter. Both are him. Robert Heinline was a little messed up.