Because psychologically they have no concept of what it is to be the opposite sex. They can only feel like they want to behave like the opposite sex. Physiologically and psychologically it is impossible, excluding the insignificant minority that have genetic problems causing them to have both chromosomes.

That's a very good point. I never really thought about that, but you are quite right. We can never truly experience what it is like to physically be what we're not, only imagine. We can also only imagine what it would be like to be in anyone else's body or life.

Yeah the right words, lets just see if they are followed by actions.

He's a politician, say no more! Let's not hold our breath.