That which does not kill us makes us stronger
It amuses me how super sanitary new parents are with their first born children. With each successive child, the parents lighten up. As a result, the younger children seem to get sick less often because they have greater resistance. For the record, I'm the youngest of 5 kids. I probably could've eaten dirt and it wouldn't have fazed Mom. I seldom get sick. On the other hand, if I ever go to my wife's country (the Philippines), I could be in trouble.