When I went grocery shopping with my mum I'd see her pay with money, then the cashier would give my mum her money back (the change). I thought that when you bought something you just got your money back. 😄 If only it was so....

When I was 4, our preschool had an activity where you stuck toothpicks in marshmallows to build balls. Pretty standard. The teacher told us that the marshmallows she had were "non-edible" and couldn't be eaten. I had moved from Korea to the US at the time, and had never seen a marshmallow. For *five years*, I believed that marshmallows were genuinely inedible.

When I was a kid I believed that if I rubbed my eyes too hard they would fall back into my head. I had no idea how to retrieve my eyes and this stressed me out.

That there’s an all-powerful deity who wants a personal relationship with me, a weak, pathetic mortal by contrast, for some reason.

My parents convinced my sister and I ( we were like 5-6 ) that if a boy shook our hand we would get pregnant. So every time an older guy, one of their friends or church members, would try to shake our hands we got into trouble because we didnt want to get pregnant. Really messed us up, actually. They refused to teach us anything about the birds and the bees and because of it we had no clue what sex was. Im talking severely sheltered to the point we were not allowed to watch anything on TV for fear they might kiss or something. They also taught us that the devil had special demons our at night to catch little girls and hurt them. So we werent allowed outside at all past a certain point. Even if they were outside and could watch us. On top of that, we were taught to serve men. As in bring their shoes, the paper, food/drinks.. Didnt matter who it was if there was a male visitor we turned into servants and would get into trouble if we didnt serve good enough or spilled something, or took too long. Really screwed us up and now we are both in therapy and have been for YEARS because of this and other things...and they wonder why we barely have contact anymore...

When I was little, I was convinced that an owl's head could not only turn 360 degrees but it could keep going around and around. (Probably got that idea from my brother) I saw one sitting on a fence post in the pasture and decided to check it out by circling him. After my 6th time of crawling through the barbed wire, I pretty much figured it out.

My mom would always convince me that the Cookies and Cream chocolate bars from Hershey's that I'd get on Halloween were poisonous, and would always take them out of my candy haul.

One day when I was 8, I caught my mom eating a piece, then I yelled "Mom, you're eating poison?!"

At that point, she knew the jig was up, and I realized she just loved cookies and cream chocolate bars. We still get a good laugh from it to this day.

If a teen around 13 years old counts as a kid:

Cows. Despite having had actual Sex Ed in school I believed that cows somehow were an exception to the rule that only pregnant/nursing females from a mammalian species produced milk. I thought they just produced it constantly.
It took a late night documentary about farming to correct me about it.

My older brother told me that if I flushed the toilet when I was filling the bathtub with water, whatever I flushed down the toilet would come out of the bath faucet into the tub. I didn't flush while filling the tub for the longest time, long after I realized he had tricked me.

I was eight, and my cat at the time once swallowed a grasshopper whole in front of me. I was convinced after that that every time I stroked her back, and her spine moved (because she liked the feeling of it), it was the grasshopper still alive inside her jumping around.