When I first learned that ketchup is made from tomatoes, I realized that that must be why ketchup is red. I assumed that mustard, therefore, must be made from something yellow. The only two yellow possibilities I could think of at the time were bananas and lemons. So for quite some time I wondered whether mustard was made from lemons or from bananas.
A childhood belief about general

others believed things like this
- I used to believe bananas came from yellow monkeysAnon
- When I was little, I thought ketchup came from ketchup trees— cristina
- My mom used to tell me if I ate mustard I would grow mustard.Anon
- That limes were unripe lemons— Alan
- I used to think that limes were lemons that weren't ripe yet.Anon
- I used to think that the title of Barry Manilow's song "Looks Like We Made It" was "Looks Like Tomatoes".— close2nd