We were once told that the Wiltshire standing stones at Stone Henge could only have been put there by the nephilim.
Now THAT is a good one! HAHAHAHAHAHA!
Basically I've found these urban legends fall into 1 or several of the following categories:
1-People who haven't had the opportunity to learn critical thinking, repeating things based on "who" told them instead of examining "what" was said. This describes a lot of dubs and it is actually the main reason they are dubs in the first place--they have no critical thinking skills.
2-People who have critical thinking skills but choose not to exercise them. Why? Laziness, fear of change, wanting to fit in, who knows.
3-People who know it's probably not true and repeat it to manipulate the listeners. (Like when I was told to lie on an assembly part about wanting to pioneer, turning down a scholarship or some such nonsense.)
None of these are legitimite excuses. http://whatstheharm.net/ j-dubs make the list!