You're right that if one person experiences something it doesn't make it a general fact. It is interesting though, that I'm not the only one having such a problem. Your last point about it is something I have thought about myself too, but I just don't know.

About the hoola hoops, you probably right there too, but as I've had the chance to think about it for years and have found no connection whatsoever, I thought anyone's 'guess' would be as good as mine.