I've been told to think of trans people as always being their true gender, from birth. Which makes perfect sense to me, but then that contradicts this discussio

I've been told to think of trans people as always being their true gender, from birth. Which makes perfect sense to me, but then that contradicts this discussion of athletics. Clearly there will be some points in time when the trans woman athlete had a biological advantage over other women, but that doesn't mean they weren't a woman at that time too.