A working/practical knowledge? Yes.
But I have knowledge of homosexuality through psychology courses, reading, personal friendships, etc.
I have never had to choose whether or not to be interested in homosexual ***. It just never crossed my mind as something I would want to do or be interested in trying.
That makes me a 15%-er, which is technically the "odd man out", but it just is what it is. I have known women who have said the same thing; they just never had a hint of interest or desire in another woman. I have also known women who are VERY hetero, but said they would try it with another woman.
I don't believe people "decide" to be hetero, gay, or bi, any more then they "decide" they like or dislike the taste of a food, or "decide" they will grow to 3 feet or 6 feet tall. It just IS, and it's part of our genetic makeup that we have no control over.
It's been proved, and I believe the studies.