When I was 4 or 5 I was startled by a white spider that somehow resembled the white "cap" of a dandelion. (Not the seeds or the petals, but the part it all rests on.)
After that, I viewed all of these plants with suspicion. Obviously, they played some part in this spider's life cycle. I inspected every plant cautiously before making my wish, then smashed the rest of the dandelion just to be safe.
This continued for a few weeks until I decided that spiders in fact do not come from flowers.
A childhood belief about plants

others believed things like this
- When I was liitle, I used to believe that if a spider would bite me than I would become Spider-Man!!!— IronManxD
- If I smelled a dandelion, I would wet the bed.Anon
- All flowers had exactly five petals and two leaves.— MD Caruso
- i used to believe the white part in fish meat is because of the fish's milk— Kim
- If you pull off the leg of a spider it will rainAnon
- I used to believe a spider monster was in my basement— Kelly bulanek