You'll see where this is going, but I can't help myself.
When I was 7 or 8 I REALLY wanted some Transformers underwear. I kept telling my mom how I HAD TO have some. The reason for this is because I saw commercials where, as kids put on the Optimus Prime underwear they turned into the big robot/semi truck themselves.
When I finally got them I was devasted. I tried pulling them several times, but to no avail. I screamed for my mom and had to have her break the horribly disappointing news.
A childhood belief about adverts

others believed things like this
- I used to think that semi truck drivers could pull you over and give you a speeding ticket.— Wolff
- I used to believe that "utensils" were underwear!— Haley
- I wanted to grow up and be a truck. Not a truck driver, a truck. Anon
- i used to think the song "walking in a winter wonderland" was "walking in a womens underwear"— stephen s
- I used to think that the Huey Lewis and the News song "I Want a New Drug" went "I Want a New Truck".— Chloe
- My mum used to tell me when the ice-cream truck turned on his jingle, it meant they had run out of ice-cream!Anon