Transexuals

[I_am_not_mafia]

Because accomplishing 'great things' and contentment have nothing to do with identifying mental illness in a person.

Ever watch a beautiful mind with Russel crow?

Dude accomplish astounding things, and in time learned to be content. However he was literally in a functional state of perpetual delusion. He saw things and people who literally not there till he died a few years back.

Like it or not mathy, dude was mentally ill by all clinical definition and reasoning, even if he was able to manage it and find contentment.

Now just because he won a nobel prize does not mean this man was suitable or of sound mind to dictate unrestricted policy for the rest of humanity.

That is no different that allowing a functional drunk get behind the wheel and drive.

You're evading the question by focusing on one thing that I said. I shall put the rest in bold for you to answer:

If someone transitions and can as a consequent function perfectly well in society. If they are accepted as such in their chosen gender and no one knows their medical history, which becomes less and less relevant to their daily lives. If they are happy and contended with their lives and able to achieve great things, then how can they be considered mentally ill?

Remember that you said:

mentally Ill people by clinical definition have a impediment in how they think and or interact with others.