They believe something which does not conform with the reality of the situation. They may feel that they are a woman, but their genetics and their body says otherwise. They may feel black, but their genetics and their body says otherwise. To another individual, they may feel/perceive "Fat" or "too heavy", but their body says otherwise.
Come on man...don't get in a huff and walk away. You very well may be perceiving that I'm in an argumentative state. I'm not. I'm very much trying to gain a measure of understanding of why we choose to view one as an illness and the other as not. So far, the best that someone has been able to articulate is that the harm is minimal and they want it real bad.
~Jeordam
Saving the Princess, Humanity, or the World-Entire since 1985