What was the enigma of which Maya Angelou spoke?

Bailey returns home one day mortified. He has just witnessed a dead black man being pulled from a pond. He wonders why white people hate black people so much. Angelou writes about the loss of innocence that black boys feel at such a young age. The enigma is the very unnatural world of hate that they are thrust into,

He was away in a mystery, locked in the enigma that young Southern Black boys start to unravel, start to try to unravel, from seven years old to death.