When I was a kid, my parents were not always honest with my brother and me.
Dad told us that steak and lobster was dangerous for kids to eat.
I believed him when he told us that brown cows give chocolate milk. (That one took years for this city kid to find out was false)
The worst one was when I was a pre-teen and a female friend told me that it was impossible for girls to break wind because they were missing some bone that was needed to do that.
I believed that one for way too many years, and boy was I unimpressed when it was proved wrong.
What dumb things did you believe as a kid?