A great little web site - http://www.iusedtobelieve.com/
About the site, in it's own words -
I Used To Believe is a funny and bizarre collection of ideas that adults thought were true when they were children. It will remind you what it was like to be a child, fascinated and horrified by the world in equal parts. The following pages will reassure you that the things you used to believe weren't so strange after all...
You can add your own to the site. If you think your beliefs were strange, check out our most common beliefs and discover that you're not alone! We also provide RSS feeds if you like that sort of thing. There are currently 63841 beliefs on the site.
Some areas of this site contain content which is not suitable for children.