Literacy
West Africa had griots, wandering storytellers/poets who handed down oral traditions of families or villages so the memory lives on.
With their fertile minds, they were capable of recalling events and people long-long passed. They were the custodians of history.
Aside Egypt’s literacy, Ethiopia was also literate and even had poetic form such as the Qene as early as 1BC, predating Christianity and Islam, nullifying the possibility of having been taught by missionaries. The Bantu of Southern Africa had a language of symbols similar to the Egyptian hieroglyphs while Southern Africa nomads also left cave paintings which tell stories of hunts and way of life.