When I was seven or eight, my mum made up this fib about a wizard named "Wizard Wiggle Wand" whose wand and hat would wiggle and he was Merlin's great-great-great-(I don't remember the exact number of greats)-nephew.
Being the gullible little soul I was, I believed her. She claimed that he did silly things like make the songbirds speak English, the ducks speak Spanish, the dogs sing (in English), our cat fly, cure all the pets at the vet, and turn the sheep pink.
She also claimed that when his magic wore off, you could feel "a buzzy feeling" in the air, like electricity. She was such a good liar that I could actually feel it in a psychosomatic way.
Eventually, she admitted to making "some of it" up.
A childhood belief about magic tricks

others believed things like this
- I used to believe that my dog could speak English, but he just didn't feel like it.— Mariah
- I remember thinking that non-English speakers were much smarter because they could speak "so much faster." Anon
- My nephew refuses to put his tooth under his pillow in case the fairy burns him with her wand.— Nina
- I used to think everyone in the world knew and thought in English, but choose to speak different languages. Anon
- "God is good, God is great, lettuce thank him for our food Amen"— pj
- I used to believe God had a pet tortoise. There was a hymn we sang that went "Great things he hath taught us"— Lozza