Not quite, some just refuse to get treatment... or were diagnosed later in life, when you can't really force anyone to go to a psychiatrist, esepcially if he/she does no harm.
That and humans in general are all crazy in some way. "Normal" is a standard we can try to achieve, but it's neither realistic nor ideal. At some point a person is sane enough that you have to say "why criticize someone for being themselves?" instead of questioning or distrusting it.