It's not that trans people don't acknowledge they are physically the sex they don't feel they are. There's a simple difference between the physicality and the psychology. It's been a proven, scientic, chemical effect.
Eh, age politics in question of law are rocky at best. I agree, there needs to be a solid consistency to what an adult is, and what a child is. That said, you called out the age politics, brace yourself for the downvotes. :$