Why do some people assume Lighter skinned black peoeple or mixed people get it easier?

I always wonderd why....im mixed but i look light skinned black. All my life i was teased for either being not black enough or jus the stereotype of black people. Like one minute soomeon would say "you look grey not black...why?" then th next someone would say"how comeall black people do this this and thbis?" or they ask me dumb stereotypical questions that they no arnt true but they just wanna get a ride out ofr me. I feel like i get treated like an alien... also some people ask my race and nationality and i say african american and argentinan, and i say i come from a black creole background and my dads side is white spaniards....they call me names like mutt and zebra, hybrid..... i dont get it?