Here's what it comes down to, Elwood..
I knew by age four, at the latest, that something wasn't right. I didn't have language to describe it, but I knew my body was wrong. The expression of this disparity that I gave the example of has been confirmed by my mother. For me, this is my truth. If you do not believe me, I will gladly give you her phone number and you can ask for yourself.
Some people know from an early age, some people do not.