in all fairness, a straight person knows as much about being gay, as you know about being straight.
Actually, gay people know a lot about heterosexual life. Virtually all of us grow up in straight families: our parents and grandparents are straight, our siblings are straight, virtually every relationship model we see in life and in fiction is of a hetero orientation. We are often assumed to be straight and raised with the expectation of being heterosexual. Many of us have dated people of the opposite sex. In effect, we have tried the heterosexual life.
Most straight people have a narrow (and often warped) impression of what it means to be homosexual. Your information often comes from rumor, gossip, assumptions, a gay pride parade, pornography, and Hollywood.