You mean, other than religion?
When I was 10, for a few weeks I thought that I was the reincarnation of Jack Kennedy.
Let me dispel another belief; It’s “Smokey Bear”, not “Smokey the Bear”. 
On topic, I thought if I dreamed or thought hard enough, I could float up in the air. Not fly, not navigate, just float. It was both amazing and somewhat terrifying depending on what story or dream I was in.
Except in England, where he is not the forest fire prevention representative.
As a kid, I took the swimming safety dos and don’ts very seriously. I was terrified of going into the water to swim after eating, for fear I would get bad cramps that would render me helpless. Not just swimming, even just wading and frolicking about in 3 foot deep water. At least an hour had to elapse after eating, though I received much conflicting info depending on who I asked.
Being the good little conspiracy theorist I was, of course I handwaved them away as distractions from the “directors” / monied global elites / Illuminati / Disney Imagineers, or some combination of the above. Either they were small scale prototypes flying much lower to the ground to give the illusion of size, or it was all just a projection inside a big dome like in the Truman Show. Certainly anybody who could maintain a fleet of sims sophisticated enough to fool the general public could also figure how to make them look believable on the ground.
The strangest part of this: At that same age, I was also a budding military aviation buff… little kid me would beg to go to the dentist just because they’d have the latest issue of Jane’s Defense Weekly in the lobby.
At the same time I was doubting the reality of civilian airliners, I was also learning about the YF-23 prototype fighters and spending long hours building SR-71 models and flying helicopters in early Micropose games.
So clearly one part of my brain believed in powered manned flight. It just never talked to that other brain, I guess. Besides, being a good conspiracy theorist was never about perfect logical consistency, anyway, but coming up with the most elaborate narratives that could half-heartedly rope in every single person, group, and idea I was even remotely skeptical of. The bigger and grander the “they”, the better! It was my own Theory of Everything (that I didn’t fully trust or understand).
I guess I took one look at Occam’s Razor and decided it needed four more blades and a rechargeable battery.
Wow. I’d like to hear how that happened. @Moriarty
When I was little I thought that saying “Excuse me” made the fart smell go away. I swear my mother told me that; she swears she absolutely did not.
I also thought that eating butter all by itself would do bad things to your tongue. I think I was told not to lick the butter off the knife because I would cut my tongue, and I attributed that to the butter (rather than the knife…).
I still currently believe I can hex free-throwers and field goal-kickers by yelling “MISS IT” and sending hex rays through my fingers.
And I as well. Because it works. Sometimes.
When I was a little kid, I believed that 1) dreams never came true; and 2) saying something in your head, while lying in bed, counted as a dream even if you were wide awake. So if you were worried, for example, about finding a centipede in your bed (something that actually happened one time, and it freaked me out), you could just say to yourself, “Fret found a centipede in her bed tonight,” and guarantee that it would not actually happen. (For that night only. You had to do it again the next night.)
As an adult, I believe, only half in jest, that it is bad luck to cook chicken Provencal on election night. What I was doing on November 8, 2016 is left as an exercise for the reader.
There is a plot point in Ender’s Game about Internet trolls influencing the world through well-constructed arguments from fake personae. I originally thought that it was unrealistic because I thought trolls wouldn’t be influential. After Nov 8, 2016, I thought that the plot point of the book was actually realistic.
Now, in the era of rage bait, I again think that the plot point is unrealistic, but because most people aren’t interested in logical arguments, and definitely not interested enough that they would go viral.
Probably the weirdest thing I believed was that life would be easy. As an only child, I had very little responsibility, very few chores, and my parents took care of everything. I think I just assumed that they always would. I carried this belief into my 20s, until I lost both parents to cancer and had no support system. Life got really hard, really fast. At first, I didn’t think I had what it would take to survive without them.
But now, as I approach 60, I realize that, in some weird, fucked up way, losing them was what I needed to develop self-esteem, independence, a work ethic, so many things that would have taken me so long to develop if they were still here and willing to support me. I might never have found out who I was and what I was capable of. Of course, I would also give anything to have them both back in my life. I would love for them to know that I finally grew up and everything turned out ok.
The first time I saw a DEAD END sign, I thought there was a pit ahead with skeletons crawling out. Never found them.
I like you appreciated your parents.
I hear people say how they miss their parents and never appreciated all they did til they were gone.
I’ve been hearing that my whole life. So I try to appreciate people in the here and now.
Not perfectly, but I do try.
As a kid as far back as I can remember the dividing line between kids and adults was always one grade ahead of whatever grade I was in. And I was always intimidated by what lied ahead in the next year. Walking the hallways in grade school and looking into the classrooms of higher grades or looking at their projects displayed in the halls I always that “OMG, that looks like some seriously adult stuff.” And if I saw an older kid or kids chatting with a teacher I assumed it was some adult like topic they were discussing.
Heil Honey I'm Home! - Wikipedia!
Thanks to the horribly inefficient traffic signals as a kid (in Cleveland), I thought mischievous if not malevolent leprechauns lived in the sewers near the light and deliberately changed the lights to promote maximum inconvenience (as they always seemed to flip red right before my mother got to the light).
I move back here as a retiree, and not much else has changed as 95% of the lights here remain on timers and not sensors. Bloody leprechauns.
Do you still look for them when the light is red? I would.
When I was a kid, I saw road signs that said “SPEED LIMIT RADAR ENFORCED”. I imagined that there was a control room at a police station with WWII-type radar screens being watched by police officers, tracking the movement of every car in the area.
Wouldn’t surprise me.
When I was a real little kid I had no clue how police radar worked. I thought it allowed the cops to see your speedometer to determine how fast you were driving. I couldn’t understand why speeders wouldn’t just cover up their speedometer so the police couldn’t see it.
While the gym teacher was explaining the rules of basketball to our kindergarten class, I somehow understood him to say that your team lost a point every time the ball hit the backboard. By the time I finally figured out that wasn’t the case five years later, my frantic, flailing, avoid-hitting-the-backboard-at-all-costs basketball technique was beyond repair.