Like you, when I reread Gene Wolfe's Fifth Head of Cerberus
I was convinced I remembered it from childhood. Part way through,
I recognized it as a story that I had occasionally had dreams about ever since I read it when I was 14 or so. Through the rest of the reading, the scenes would come to memory as if I were being reminded of the actual events, rather than of having read about them.
Nobody has mentioned Chinua Achebe. Everything of his I have read is excellent, in particular No Longer at Ease. He's a Nigerian from Iboland and has interesting viewpoints on cross-cultural contacts.