I understand where you are coming from juroara to some degree.
It seems that people over sanitize.
An example is my wife's encounters . She cleans houses. I was talking to her about this discussion last night. She had told me that her two cleanest houses, ones she described as, " You could eat off the floor BEFORE I clean them." They are the people who are always getting sick when they go somewhere. They come in contact with germs that their own immune system never come in contact with.
Schools and day care centers are huge breeding grounds for germs, colds, etc. But you don't see teachers and the like getting sick ever other week or so.

ah ahahaahhh a ahAHHH CHOOOOOOOO!!!!!!!!!