Arachnaphobia - fear of spiders - always struck me most in the bathrooms. I was afraid to sit down without check under the seat to make sure there were no spiders coming up.
Of course, when camping in public camp sites, this is still my concern :-)
A childhood belief about fear of

others believed things like this
- I know this isnt a huge funny belief, but I used to think that all spiders were poisonous. I love spiders now!— Sammy
- Farts really are Barking Spiders, right?Anon
- When I was a small boy, I used to believe there were spiders in the toilets.— nicolas, a French student in 8th grade
- I used to think spiders came from rosebuds. Don't ask. It was a traumatic experience.— Zog
- I used to believe that spiders were mutated rats that were shrunk!— Quako
- i used to think that little tiny spiders would grow big while my mom wasn'r looking and eat me.— rodog