In his work Decolonizing the Mind, Ngugi wa Thiong'o has a very specific meaning when he speaks about the "quest for relevance."
For millennia, various parts of Africa had been subject to outside rule ("colonization"). Therefore, most of what African children learned in schools was not their own native literature and history, but the stories and histories, and cultures, of other nationalities.
Ngugi wa Thiong'o himself grew up speaking and writing in English. His first novel, written in English in 1964, was Weep Not, Child. However, after his embrace of the tenets of Fanonist Marxism, Ngugi wa Thiong'o renounced both English and Christianity, and changed his colonist name, "James Ngugi" to the one he is now known by.
After a stint in both prison and years in exile, Ngugi wa Thiong'o finally returned to his native Kenya were he was instrumental in the founding of the Kamiriithu Community Education and Cultural Centre, and this community center is a large part of what the author and activist means when he talks about the "quest for relevance" in Decolonizing the Mind. An article for the "Global Literacy Project," explains Ngugi wa Thiong'o reasons for emphasizing what is "native" to Kenya:
"According to Ngugi's way of seeing, you can't study African literature without studying the particular cultures and oral traditions from which Africans draw their plots, styles and metaphors."