I think we have some of these things in the Netherlands as well, people believe (among others):
* Air draft causes a stiff neck
* Freezing meat twice and eating it will make you sick
* Cold in general will make you sick ("catch a cold")
* If you hold your poo to long, you can never poo (well) anymore (from the grandparents, pretty sure they believed it, actually it may be true to a certain degree but they used to go when one need to go asap.)
* Air draft causes a stiff neck
* Freezing meat twice and eating it will make you sick
* Cold in general will make you sick ("catch a cold")
* If you hold your poo to long, you can never poo (well) anymore (from the grandparents, pretty sure they believed it, actually it may be true to a certain degree but they used to go when one need to go asap.)
I'm sure I'll come up with more.