For a man to call himself a woman can not change his molecular structure. Since boys are made of snips, snails etc., while girls are made of sucrose and spice, that that DNA molecular structure can not be changed by calling it a different name. It would take a great deal of effort to turn a snail into sugar or spice. Even the basic elements are different.
reference: What are little boys made of?
What are little boys made of?Snips, snails
And puppy-dogs' tails
That's what little boys are made of
What are little girls made of?
What are little girls made of?
Sugar and spice
And everything nice [or "all things nice"]
That's what little girls are made of