When I was in 5th grade health, they taught us about AIDS. No other STDs, just AIDS. Why they bothered trying to explain something as complicated as AIDS to 5th graders, I have no idea. All it did was make us paranoid. They showed us a video that talked about how you should never do the blood-brothers thing, or EVER have unprotected sex, because if you did, you'd get AIDS. Yet, at the same time, they're telling us "You can drink from the same glass as someone with AIDS and you can touch them. But you can't touch their blood!"
They never explained the part where you have to share bodily fluids with someone who already has AIDS to contract it. So up until middle school, I thought that to contract AIDS, you just have to exchange blood with ANYONE, and that it would sorta have a "catalyst" effect, I guess. It took my parents to finally explain it thoroughly to me.
A childhood belief about classes

others believed things like this
- I used to believe that you could catch AIDS from just looking at a nud girl. Good thing I was WRONG— Mbm4615
- I thought a contract killer was someone who kills people who break a contract— Nate
- when I was young, I heard that blood had iron in it. I thought blood was red because it was rusty.— Hunter
- I used to believe that guns shot out blood because everytime somebody shot a gun in a movie you saw blood.Anon
- When I will little I used to believe that when you got married, you signed a contract to order a baby! LOL— Kriatina
- I used to think that blood flowed down one leg and up the other.
And I'm applying to medical school....— Nat