Sex was more interesting when we knew less about it; when we proceeded from murky impulses rather than easy familiarity. Consider the Victorians, slipping off to secret vices and how much more fun they had than today's Jerry Springer guests ("My girlfriend is a dominatrix"). The intriguing border between the genders must have been more inviting to cross when that was seen as an opportunity rather than a pathology. One of the many virtues of "Boys Don't Cry," one of the best films of the year, is that never once does it supply the tiresome phrase, "I am a man trapped in a woman's body." Its motto instead could be, "Girls just wanna have fun." Teena Brandon doesn't think of herself as a sexual case study; nothing in her background has given her that vocabulary. She is a lonely girl who would rather be a boy, and one day she gets a short haircut, sticks a sock down the front of her jeans and goes into a bar to try her luck. She is not a transsexual, a lesbian, a cross-dresser, or a member of any other category on the laundry list of sexual identities; she is a girl who thinks of herself as a boy, and when she leaves Lincoln, Neb., and moves to the town of Falls City in 1993, that is how she presents herself. By then she has become Brandon Teena, and we must use the male pronoun in describing him.