Frenzy, if one does not share the same feelings/hormone levels (the two are related) as me, we are different, and full empathy is similarly impaired. Females are different to me, hence my irritation with their constant bellyaching. I also treat them in a different way to males Similarly, homosexuals etc. are also different, and hence get treated slightly differently. I do not, for example, engage them in crude, vagina-related banter. Not that I do that with anyone else, you understand. But the point is I make allowances for the differences between us, just as I adjust for age, religion, gender etc. And, hence, if we wish to maintain a polite society, it is impossible for me to converse and interact in an identical manner with people who are gay and those who are not, or those who are female etc. If black people are culturally different to me, I will similarly be unwilling to interact with them in a 'normal' (ie white/male/middle class type interaction), but if they come from my culture, due to the lack of major differences between us, 'normal' interaction becomes possible again.
Note that if I were, for example, engaging in a science-based debate, it would be a science-type interaction, which means that the above interactions are irrelevant. And in non-normal situations, my response will be similarly different. Hence, I am not completely incapable of engaging in situationally normal interactions with different-type people. But where it matters, I cannot without breaching the politeness ruleset. And, hence, I am unable to comply with your implicit request that I treat everyone in a quasi-identical fashion, which, in turn, prevents them (if I am everyone) living a 'full' life, if I read what you were saying aright. Sowwy.