https://www.quora.com/What-are-some-facts-still-being-taught-in-school-that-have-been-proven-to-be-false The hymen is a stretchy membrane, and it's shaped like a flap, stretched a little way across the vagina. When women are aroused and are naturally lubricated (sometimes aided with lubrication jelly or gel), the muscles and the hymen stretch, allowing for penises, fingers, and sex toys to enter, and for babies to exit. When a woman is not fully aroused, or not aroused at all, the hymen and the muscles of the vagina do not stretch and are not lubricated, so when intercourse happens, the hymen membrane is torn. It is this tear that creates the 'first time pain' and the blood. This tear happens whenever a women is not lubricated and aroused: that could mean the first, second, 30th, 60th, 100th time that a woman has sex. However, by perpetuating this 'myth' uneducated teachers are creating a self-fulfilling prophecy: by telling girls it'll hurt the first time, they will not relax and allow themselves lubricate and stretch, thus causing the damage to the hymen. And so on and so forth. The reason as to why this fact is not taught in schools is probably because sex education is not taken seriously enough. But there is also an aspect of misogyny and sexism, especially when the hymen is used as a measure of virginity - which is an outdated and useless idea, leading back to when women were the property of their fathers and husbands and has no place in society now. Not only that, but if - like in America - there is a religious aversion to sex (such as taking the view that sex and masturbation is sinful) then sex education is corrupted into 'Abstinence Only' classes, which tend to be misinformed. If you go to youtube and search: "You Can't POP Your Cherry (HYMEN 101)" the first video by lacigreen will tell you more about the hymen.