The article The Brave New World of Gender Nonconformity: Pregnant Men opened a number of details about people who are confused about their gender. There are people (and they are around us, be sure!) who were born one sex, and later realized they were the other sex! One of the stories (links given after the article) is about a boy who began his studies in a school for girls. He (or she, I'm not sure) confessed that all his life he has been hating his being a girl and knew he was a boy by nature.
Now he has a girlfriend and is happy with their relationship.
There are quite a number of such people, and they are suffering from misunderstanding, from lack of money (to be operated), from many factors in the society which don't let them be the ones they want to be.