Here's what I think......that for people who feel happy in their gender ident/sexual partner choices, there is no need or right for them to understand those who are not similarly content.
That no one has a right right to require to understand or to dismiss or disagree with the validity of the the gender ident/sexual partner issues of others because they don't understand them. (I seem to have strayed onto portmanteau sentence territory again).
What is necessary is good manners.
At minimum to have the attitude that other people are entitled to be different from ourselves in ways that we cannot understand or empathise with provided what they do/say/feel does not injure others. That when we address or describe anybody, we should use the terms and words that they would choose to describe themselves.
To behave from the premise that while understanding someone might be helpful in accepting them; it is not a prerequisite.
In all honesty I don't understand gender dysphoria. As someone who is cis gender, it lies totally outside my experience and its not something that I can imagine. I "know" that I feel female but I would be hard put to describe what that feels like and I am fairly sure that what it feels like to me differs quite a bit from what it feels like to many other women. I wonder how much of an artificial construct "feeling female" or "feeling male" may turn out to be...which in turn leads me to wonder what someone who feels that their biological gender is at variance with their psychological gender is actually feeling because so many of the external signs of female gender, in particular, eg wearing skirts, high heeled shoes, make up and so on, are social conventions.....as I said I don't know and don't understand.....but that's fine. I am not required to and have no right to......all I have to do is accept that its a valid way for other people to feel.