it's objectivly not normal. it's not like being gay. it's not like loving a black chick. thinking you're the opposite love is not a healthy thing to think. that's why it's literally a mental illness
There were plenty of people with the exact same frame of reference for homoloveuality.
a) it's not normal because men and women are meant to be together
b) it's not normal because the bible says so
c) it's not normal because I find gay love repulsive
d) it's not normal because two dudes can't procreate
There isn't anything different between those ideas and what you're saying right now, except that homoloveuality has become largely accepted in Western society whereas transgender identities are still on their way.