After reading about the Allison Bailey case today, I was thinking about how someone simply saying they identify as their non biological sex was to be accepted as such without question and how crazy this was.
And it came to me how this could be compared to age. So please hear me out and tell me if it makes no sense. And apologies in advance for going off on a tangent. 
There are some people who say that they do not feel their age and feel older than they are or younger than they are etc. And of course that is fine. People can feel how they want and dress and behave how they want provided they are not hurting others.
So an example: A person might say they still feel like they are 20 years old and wish to still go out partying every night; however their age is actually 70 years old. Just because this person “feels” they are 20 years old and demands others accept this as a fact, should everyone accept that their age is 20 despite the fact that their biological age is actually 70?
The answer is no; no one would ever accept their age is 20. Their age is what they were born with, it is a scientific, biological fact. It cannot be changed.
However, no one would object to the 70 year old going out partying every night should they wish to.
But the fact is, a person simply cannot claim to be a certain age based on how they “feel” and demand that others accept this as their age. Their age is a biological truth which cannot be changed and it is what it is. But of course, the 70 year old is free to act as if they were 20 years old should they wish to and no one would give a damn. Just don’t say you are 20 years old when you aren’t.
Just like if a 40 year old biological male demanded to be allowed in to a children’s play centre because he “feels” that he is 10 years old and therefore should be accepted as a child. Yet everyone can see he is not a child; he is a grown, adult man. His mature, adult body is evidence that he is not a child. Yet he is demanding others accept that he is a child because he “feels” he is a child and should be treated as such.
Should he be accepted as a child due to him “feeling” he is a child or do we accept the scientific and biological evidence, as well as what others can clearly see; that he is NOT a child and cannot be allowed in to children’s spaces.
A person is what they are. They are free to act how they want provided they are not hurting anyone; just don’t claim to be something which you biologically and scientifically are not and can never and don’t demand that others accept what is not scientifically and biologically true and never will be true.
(.......And breathe!)