Very well. Let's not be extreme. Let's take a not-unusual social problem.
X feels most himself (or herself, it doesn't matter) when he is holding forth at length and in detail about one of a very few subjects that fascinate him. It never occurs to him that other people don't find the subject fascinating and his exposition of it rivetting.
I (and many others) experience this as excruciatingly boring.
So: do I have to sit there and put up with him "expressing an important aspect of his authentic self"?
If so, for how long do I have to put up with it, and how often? Am I allowed to make a polite excuse and extricate myself when I begin to feel bored?
Am I allowed to ever actually tell him that he's boring me to oblivion and that I want him to stop, or do I have to maintain the polite fiction that he isn't boring at all?
Do I have to convince myself that what he says must be interesting and that if I don't find it so, the fault is in me?
Do his feelings and needs take priority over mine? If so, why?