I've believed that theory for years now. My kids very seldom got sick. They didn't have bad allergies. My brothers boys, and the neighbor kids were always sick and always taking antihistimines. I think JP has only been sick 1 time, and boy does that boy get dirty:) and cold, and wet. We can't keep him out of the mud:). He loves it. People just don't get it that cold, wet, and dirty is not what makes kids sick. Germs do:)
Becky
I encourage my kids to get outside and get dirty. If they are too dirty to come in I make them strip on the back porch. If it's summer, I'll hose them off before they come in.