merrymouse, quite. And this is the shell game, of course, and why they have played silly sods with the definitions - in the old understanding 'transition' meant moving from one state to another. Now, obviously no one actually believed it was possible, but it was a reasonably accurate term for the appearance of things.
But now the umbrella of trans is so enormous it includes essentially everyone except Barbie and Ken, the terminology of 'transition' has actually become detrimental to the people who stand to gain most from the movement's power play.
So, what we're seeing is a gradual phasing out of the terminology entirely - and for that to have the traction it needs, the words 'woman' (and 'man' to a lesser extent) must be emptied of any quantifiable meaning.
Because, as you point out, if someone claims to be transitioning, there must be an idea of what state they are moving from, and what to.
If, however, as seems to becoming the case, the claim is not about 'transition' at all, but about 'identity', then people can claim to have been female all their lives, even when it was demonstrably not true, because woman and female no longer mean anything beyond an indefinable feeling.
No wonder old school transsexuals are so pissed off with this - the movement will erase actual women first, and the next logical step will be to erase transsexuals too, because they show up the nonsense so very clearly.
This is why I am so adamant about not calling them TRAs, because I actually think that they aim eventually to get rid of the notion of transition entirely. The aim is control, and the heart is Anti-Woman.