When I was a very young child and heard the word nigger for the first time I thought it was referring to some kind of insect like a dung beetle.
Later, I saw a nigger on the TV and I hated it and was angry that something so ugly could exist, because brown skin is ugly, and being ugly is morally wrong.
Then I realized those ugly things on the TV were niggers, and it all clicked and I hated them forever. I was like 5 at the time.
That's how it started for me. Disgust at the realization it was even possible for people to have poo colored skin.