Another one from when I was very young was about gas stations/filling stations. I always marveled at how those gasoline pumps with the rotating digits can have so much fuel available to dispense to vehicles despite being only 4 or 5 feet high and maybe 2 feet thick by 2 feet wide. 
When I was 6 or 7, I really believed that when you dropped a letter in a mailbox it entered a tube that somehow transported it directly to the recipient. Something like the pneumatic system that some department stores had for internal communications. But I would not have known about them.
When I was 3 or 4, I thought wind was created by trees shaking.
And that skyscrapers were planes that left contrails (JFK, maybe 20 miles away).
After seeing an illustration in a kid’s science book I got the idea that gravity failing was a natural disaster like earthquakes. I was pretty freaked out for a couple of weeks and whenever I went outside I kept an eye out for things I could hold on to so I wouldn’t fly off into space.
I once got lost driving in northern Vermont and thought I was in the U.S. when actually in Canada.
This probably was in the 1980’s. Now there are barriers set up so even I would know.
OK, that’s your weird belief. 
David Brin had some fun with this in the third book of his first Uplift trilogy.
I thought that people who spoke a foreign language had to translate mentally what had just been said into English in order to understand conversations.
My mom assured me that this wasn’t the case. They understood those weird strings of sound immediately, without translating. Blew my mind.
I thought there was a person inside the pole of a traffic light that changed the lights.
You mean that doesn’t work?
I was one of those kids who thought I would get sucked down the drain if I didn’t get out of the tub before the plug was pulled. Weird, but from what I gather, not uncommon.
When I was a kid, we called dragonflies sewing needles. I believed my dad when he told me that when someone lies, sewing needles will sew their mouth shut. I pictured the shrunken heads with the thick black thread.
Until I was about 7 years old I thought the poop inside you was stored in your butt cheeks.
Ha ha ha ha!
This is a fun thread!
When I was about 5 and was learning to read, I misread the highway signs at the end of No Passing zones as ‘PASS WITH CAR’, rather than ‘PASS WITH CARE’. I understood that to mean that only cars could pass on the highway, but no trucks or pickups. And, indeed, the few times when I rode with Dad in his old farm pickup on the highway, he never passed anybody, which validated my belief.
Actually, The is his middle name, short for Theodore, in honor of Roosevelt.
The Kennedy thing?
He was killed in 1963. I was born in 1978. The timelines worked out.
I grew up as an evangelical fundamental Baptist in the 1990s - the peak era of “What Would Jesus Do” and the Tribulation and “Left Behind” book series. I devoured the Left Behind books, and was ready to identify the start of the Rapture and Tribulation (even though this isn’t even specifically laid out in Revelation). I have since deconstructed, and consider myself barely spiritual/agnostic. However, parts of me believe Donald Trump is the Antichrist predicted by the Tribulation fanatics. The Antichrist was predicted to be loved by Christians despite not being a godly person, to survive a alleged head wound, and to deceive other countries into giving him elaborate gifts (Air Force One was specifically mentioned in the Left Behind series). Yes, I know this is a crazy conspiracy theory - but I almost can’t help but wonder if it’s true.
If it helps a bit, the most common interpretation is that the Antichrist in Revelation was modeled after Emperor Nero. He has been dead since the year 68, so don’t worry.
Plus, Nostradamus predicted the Antichrist would be Mabus
Clearly, the Ma is for MAGA. And Bus is because Trump is a business man.
it all adds up!
Same here. When they hit it anyway, I figure I didn’t get the timing right. You have to shout it at the exact microsecond when they’re releasing the ball or just as their foot is making contact, so you can startle them.
No, don’t ask me how that works when you’re watching it on TV. IT JUST DOES. Sometimes.