If you're African-American or Black- Why do people of our race penalize us for being intelligent?

All my life they've said I "wanna be white" and called me "oreo" and "coconut". I've even had my books taken from me so that I couldn't read. All because I take joy in being an intelligent person and like learning new things. Since when did being smart and articulate belong exclusively to whites? If you've behaved that way, or called someone those names, what is your reasoning in doing so?