How about boys who think they are dogs or cats? They do exist, you know. Should we go along with that as well? How about boys who think they are a god, or boys who think they are angels? If it's all about the person's "heart, soul, brain," then does that settle it in those cases? Do we reach a point where impressions become delusions?
Talking about delusions, it's amazing how our abandonment of God has led us to the point of not even being able to figure out what we should call boys and girls.