My neice was convinced that the line about 'The girl with kalidiscope eyes' in the Beatles song "Lucy in the Sky with Diamonds", was actually 'The girl when Kalidis goes by'. I'm not sure who she thought Kalidis was, but she couldn't be convinced otherwise.
A childhood belief about misheard lyrics

others believed things like this
- I thought that the line was "Lucy in the Sky with Linus" (not lucy in the sky with diamonds)— Forrest
- a friend was convinced that his school was an asylum, and couldn't be convinced otherwiseAnon
- When I was younger, I saw Madonna's video for "Material Girl". I thought she was singing "I'm a Cheerio Girl"!— Greg
- When i was little my mum convinced me that if a cat spat in my eyes i would go permanently blind. — Louise Atkinson
- I always thought instead of saying "Im a material girl" Madonna was saying "Im a cheerio girl".— Tiffany
- I used to believe that the words to Michael Jacksons "Liberian Girl" were "librarian girl".— Paul