Question, how do you wake up and feel like your another sexuality?

Im asking this because a lot of gay guests on....Political talk shows I listen, I wont name any. One said he used to have sex with a lot of women but then became gay. So how do you just wake up one day and say "You know, i dont like women anymore". I am not Homophobic, I dont care what you do in the privacy of your own home, and I simply dont care enough to say you cant get married. So do you care to explain?