I used to believe that the way you had sex was to take off your shirt and show your chest muscles - this would make the woman excited and she would want to press herself against you (fully clothed) and kiss you, thereby getting pregnant. You did not make her pregnant if you were wearing your shirt.
I attribute this belief to way too many Hercules and Sinbad movies as a child.
sex
7,896 beliefs in this area

When I was very young I had seen mild sex scenes in movies and actually walked in on my parents before. I had the basic idea about what sex was, but had never seen a penis or vagina during sex so I though you would just wrestle around naked and kiss. I also thought this would get you pregnant every time.
When I was little I had a dictionary, which I used to look up any word I did not know. I heard the word 'orgasm' on the television, and when I couldn't find it, I asked my Mum. 'Oh, it's nothing to worry about, it's just like a big sneeze', she said - which I have to say I believed until I had one...
When was about 7 years old, my family went to sizzler and my mom let me go to the bathroom by myself.
I found an empty tampax carboard tube on the floor. I had never seen one before. So I brought it out to the table announcing that I had found a "telescope" in the bathroom.
My grandmother (having never used tampons apparently) didn't see what the problem was about me playing with this object.
Natch my mother and sister were mortified! I still laugh (and am grossed out) about this incident to this day!
I used to believe…
tampax tampons used to come in these cool cardboard applicators, and if you gave them a good intentional whack on one end, well then the cotton tampon would be propelled out like a soft bullet.
As a young boy growing up in a house full of women, I had no idea what a tampon was. But I knew quite well what "cotton rockets" were. My mom arrived upon the scene to witness the yard covered in unused tampons that i had been shooting here and there, under the sly pretext of Star Wars battles and Spider Man adventures. My dog was chasing after the tampons and chewing them up. It was sunny, and I remember that that was a really fun afternoon.
I can't imagine what she thought. I think I got the "facts-of-life" intro speech not long after that.
pick of the bunch
I used to think that babies came from urine.
When I was very young, a boy at school told me that sex involved a man putting something into a woman's belly button (a worm, he explained to me) and that worm would eventually gestate into a full grown baby. He told me that boys practiced by putting their worm into holes cut into bars of soap. This made perfect sense to me, as babies in pregnant women appeared to be centered around the belly button. The first time I saw the umbilical cord on TV, my belief was confirmed, as I figured that was the vestige of said man's worm, clinging for dear life.
When I was 7 years old I found some pads under the bathroom counter. I thought they were knee pads. All the neighbors had a good laugh to see me riding my bike up and down the street with sanitary napkins stuck to my knees and elbows.
When I was three, I saw an anatomically correct male baby doll, and asked my mother what the squiggly between its legs was. Before she could answer, I said, "Oh, never mind -- I know what it is! It's a kicker!"
She let it go at that.
Having never seen male reproductive organs as a child, and being confused by the variety of terminology (penis, dick, balls), I decided it must be like a line of fleshy balls strung together, like pearls. For years I was horribly embarassed by pearl necklaces, but for quite a unique reason!
The nursery term for the penis in my family was the Greek word for dimple (or seal, as on a letter or document), which is "voulla." This was not an ideal choice. For one thing, there is a Greek girl's name (unrelated, I think) that sounds just like it, and I always wondered what kind of nuts would name their daughter "penis." For another thing, a friend of my grandmother's came up to me one day and said, in Greek, "oh what a cute kid you are, and you have two dimples." I vehemently protested that I had only one, much to her initial bewilderment and subsequent convulsion. (I was told about the incident many years later and have no memory of it, but I would like to think that she then said, "sure you have two. One here and one here.")
Many years later, long after learning the proper (and improper) terms in English and Greek, I was on a trip to Greece and was quite amused when our taxi passed the "Voula Beach Hotel."
pick of the bunch
I believed that my parents didn't have to have sex in order for me to be made. When my cousin told me that everyone had sex to have kids I called him a liar.
when my dad and his sister were teenagers he would see her eyelash curler on the counter near the sink. untill he married my mom, he was convinced that the eyelash curler was a tampon remover!
Not wanting to discuss reproduction with me, my mother told me I was adopted from a band of gypsies. I believed her until I was 12 years old and she broke the news. I was kind of sad. I mean, come on, how many people do you know that are adopted by gypsies?
I had heard about ejaculation, but
had never done it myself. Somehow
i got the impression that it was
just peeing whilst having an erection.
As you could imagine, I didn't see
what all the fuss was about.
I saw that boxes of tampons often showed up in our bathroom. I asked her what they were, and she explained that they were for when you got your period and they would soak up the blood. I assumed that periods meant you were peeing out blood, and tampons were a kind of specialized toilet paper that could stop this.
One morning upon waking up in my parent's bed (I was about 2), I gleefully pulled my pants down and showed my mother my penis.
"That's my penis! Show me yours!"
I was nearly catatonic when my mother explained to me she didn't have one.
In the fourth grade the girls had to watch the "period movie". In the movie it mentioned that "soon after you start to get pubic hair.. your period will follow." So I thought that if I shaved it off I would never get my period. I would shave it often with my fathers razor in the bathroom. To this day ... he doesn't know.
In my young, impressionable years, my sadistic older sister informed me that when you get to 8th grade you have sex education, and the teacher would randomly call on a boy and a girl to come to the front of the class to drop their pants for illustrative purposes. The rest of the class would gather around and stare while the teacher would point out various anatomical features. I lived in fear of being the unlucky victim of this mortifying exercise.
Fortunately, when I finally reached 8th grade, the teacher picked someone else :)
I used to believe that your vagina and urinary tract were one in the same. I didn't understand how you could have your period for a week straight and be able to wee at the same time.