The 5 Most Important Things They Never Taught You in Sex Ed

5 Myth: Condoms Are Effective 97 Percent of the Time

"You didn't use protection?" is the default exclamation when anyone who isn't married and between the ages of 20 and 35 gets pregnant. It's also a pretty loaded question, because "protection" is generally cultural shorthand for condoms, which suggests that pregnancy would have been impossible had the couple in question had the foresight to wrap the penis up in baby-thwarting latex. It makes sense -- as the labeling on most Trojan packages will tell you, condoms have about a 97 percent efficacy rate. Sure, 3 out of every 100 couples are going to get a squealing, sleep-destroying surprise, but what are the chances one of those people will be you?

As it turns out, the chances that your condom will betray you are much higher than you think. That 97 percent success rate everyone quotes, while technically correct, is stretching the truth thinner than a rubber pulled over a basketball. The actual success rate of condoms is around 82 percent, leaving their failure rate a whopping 18 percent -- six times higher than advertised.

The figure on the box is only referring to how often those failures result in pregnancy when the condom is used perfectly. This doesn't mean simply using a condom every time you have sex -- there's a surprisingly specific set of instructions you need to adhere to in order to prevent unwanted man juice leakage, sort of like the rules about keeping a Mogwai from turning into a gremlin. If condoms are your sole method of birth control, chances are one of you would be an accidental parent within a year.

When you open the condom package in the heat of the moment, do you always carefully examine the product to make sure it has a reservoir tip, and if not, pinch the tip, leaving approximately one half-inch space in which sperm can collect? No? That's a shame, because that's incredibly important. Otherwise the condom could overflow, or straight-up burst like one of the Nazis from Raiders of the Lost Ark. Do you always remember to slap on a whole bunch of lube? Failure to do so will increase chances of the condom breaking due to excess friction. If you did remember to use lube, did you make sure it was water-based? Anything other than water-based lube will dissolve the latex of the condom. We're beginning to think that the high success rate boasted by proper condom use is because 97% of people no longer want to have sex after doing all that bullshit.

And that's just putting the condom on. Literally anything else that happens during the actual act of intercourse can decrease a condom's effectiveness, like pulling out too early or too late, getting the condom twisted around or crooked -- basically all of the haphazard, tumultuous rolling around that makes sex sex. That's like designing a raincoat that will fly apart with the smallest gust of wind.

We're not saying that you should totally abandon condoms (they are 0 percent effective in that scenario). Just don't rely on them as your sole source of de-babyfication, and make sure you're following all of the directions instead of slapping one on like a drunken clown trying to tie a balloon animal around a tree.

4 Myth: Wet Dreams Are Something That Only Teenage Boys Have

The term "wet dream" is one of the grossest bits of slang to ever make it into other walks of life ("This matchup is a basketball fan's wet dream!"), and every teenage boy can remember finding out what it was, one way or the other. If you go to a teen health website they're happy to tell you that, "... a wet dream is when semen (the fluid containing sperm) is discharged from the penis during ejaculation while a guy's asleep." Though we suppose kids today would be more likely to consult Urban Dictionary, which will tell them pretty much the same (that it's "what happens when you ignore your penis for too long and it decides to plot out revenge"). It sure is crazy to be a male going through puberty, right?

But as happens so often with anything having to do with sex, the ladies get ignored completely ... even though 30-40 percent of them orgasm in their sleep, just like the dudes. Hilariously, scientific studies on this subject discuss female wet dreams like they're trying to track down the Loch Ness monster ("... there is an extensive lack of information ... Since 1970, only one new study concerning female nocturnal orgasms has been published ...").

If your Sex Ed class covered this, consider yourself lucky -- the Internet is full of adult women from all over the world asking sex advice columns if there is something wrong with them.

On top of the lingering idea that a sex drive is something that only boys have, there's the fact that it simply doesn't happen to all women (unlike wet dreams for males, which are nearly universal). So if a confused young girl asks her mother if her orgasmic dream about Liam from One Direction is a normal part of growing up, she's more likely to get a response of, "No, either the real Liam broke into our home last night, or you have been molested by an Incubus. In either case, you are no longer a virgin, and must be banished from the village."

3 Myth: For Women, Birth Control Is as Easy as Taking a Pill

Okay, so it makes sense that condoms can be tricky -- those penis balloons aren't exactly high technology, after all. Birth control pills, on the other hand, are often considered the contraceptive equivalent of a magical potion; simply remember to take it on time, and boom, infant-free sex will paint your horizon for the foreseeable future. Sure, it doesn't do much to prevent STDs, but with a success rate of 99 percent, you'll never need to move out of that one-bedroom apartment until you're absolutely ready.

Slow down, friend. Don't go smashin' nasties all willy-nilly yet, because the real success rate of the pill is about 91 percent. This is partly due to people forgetting to take them, but even those who dutifully toss one back every day at their scheduled time can still find themselves hilariously pregnant, due to a few surprisingly easy-to-make mistakes.

The first and most common error is timing. The pill is not an instant drug; it takes at least seven consecutive days of use before it can be considered effective, and if you screw up either the "seven" or the "consecutive" part of that equation, you're in trouble. And while missing one pill won't put you at too much risk, waiting too long to take a missed pill (or missing more than two in one pack) can lead to the creation of a tiny person who will spend ten years thinking you're awesome before settling into tolerating, ignoring, or resenting you for the rest of your life.

On top of the timing issue, several common medications can interfere with the pill in a handful of ways that all boil down to making it way less effective than you're trusting it to be. Antibiotics, migraine medicine, ascorbic acid, St. John's Wort, and even some dandruff-treating shampoos will totally hamstring your birth control to the point where you're rolling the baby dice every time you have sex.

Conversely, if you're on any other kind of prescription medication at the same time, there's a good chance that the pill will sabotage it. You're essentially swallowing a big ol' wad of hormones to tinker with your body chemistry, so even medicine that you've been on for years can suddenly stop working or turn against you in disastrous ways. This includes many pain relievers, antidepressants, corticosteroids, beta-blockers, and even goddamn caffeine. You pretty much have to choose between the pill and being able to function normally.

2 Myth: Girl-On-Girl Action Can't Transmit STD's

Well this one is obvious. Even if you've only seen lesbian sex via a series of low-budget videos, you know generally how it works and that there are no fluids being exchanged. And this means, as every health class taught in the last century will inform you, that viruses have no means of hopping from one partner's blood stream to the next. Right?

It's true that, due to the slightly smaller amounts of mucosa-on-mucosa action, lesbian women are less susceptible to certain STDs, like gonorrhea and HIV (although it is still totally possible to contract either disease during lesbian sex). However, when it comes to the vast majority of STDs, lesbians are at pretty much the exact same level of risk as anyone else.

And there are even certain sexually transmitted infections that you are more likely to get if you are a lesbian, such as bacterial vaginosis, although why BV is more common in lesbians than in heterosexual women is something that science hasn't quite figured out yet. One study on the subject suggested that the culprit could simply be a lack of information on safe sex for homosexual couples. According to the research, many lesbians use shared sex toys during penetrative intercourse, unaware that this can spread infection more easily. They're not being neglectful or anything -- it doesn't occur to most people to put a condom on a dildo, because sex toys are a topic only the most progressive of sex ed classes are willing to discuss.

But all of these strange mysteries of female sexuality really come back to the same problem ...

1 Myth: Pretty Much Everything You Think You Know About the Vagina

Considering how much time men spend thinking about it, most of them know very little about the vagina (just ask any woman). But even females get the details wrong, because what little information we were given in school is woefully inaccurate when it pertains to certain aspects of female genitalia. For example, you probably think this is a clitoris:

No way, man. This is a clitoris:

Yes, that tentacled monster wrapping itself all the way around the vaginal canal and extending back into the ether is the real clitoris, which, despite being the size of a damn spaceship, is apparently still impossible for some guys to locate. The reason you've probably never seen it diagrammed like this before is because we still don't really know that much about it, primarily because no one has ever bothered to research it. Are you starting to notice a theme in this article? Particularly how, until the last few decades, science has regarded female anatomy as a forbidden chamber of mysteries?

Here's what we do know: the clitoral structure is composed largely of erectile tissue, which can be activated much in the same way as male erectile tissue (yes, lady-boners are totally a real thing). Consequently, some researchers theorize that the G-spot both is and isn't real, sort of like Santa Claus -- instead of being an entity of its own, the sensation attributed to "hitting the G-spot" could simply be stimulation of another part of the clitoral structure.

For a decidedly less fun topic of vaginal discussion, let's move on to smegma, which is something else you probably never learned about, possibly because of its heinousness. Smegma occurs when a lady's natural lubricant, sebum, builds up and hardens within the creases of the clitoral hood, essentially turning the most sensitive part of a woman's genitals into gross biological pottery.

Of course, the clitoris is not the only piece of female anatomy that reasonably educated adults still believe ridiculous myths about. You know those assholes who are always talking about how women have "tight" or "loose" vaginas? Well, here's the thing: unless you're an older lady who has pushed a handful of children out of her person chute, there's absolutely no such thing as a loose vagina, and it certainly isn't caused by having tons of sex. The vaginal muscles are relatively similar to the muscles in your mouth, which means it will not lose its shape from frequent sex any more than your mouth will bonelessly deform from eating too many double cheeseburgers.

In point of fact, if a lady is properly aroused, the vagina actually should be kind of loose during sex. If she feels tight, it probably means she's not that into it, so maybe hold off on the back-patting and fist-pumps there, guy.

Mimosa is a public health fanatic and professional pirate. You can follow her on twitter @MimosaThomas.

For more things you could have benefited from in school, check out The 10 Most Important Things They Didn't Teach You In School and 21 Lessons You Wish They'd Taught in School.

Spread some appropriate sex knowledge, click the Facebook 'share' button below.