There is this weird thing about cleanliness that permeates some quarters of Anglo society. It's like avoiding lifting anything because you might strain a muscle. Some people don't get that human beings have immune systems. They work just like every system in our bodies: they respond positively to stress. So the more bacteria you interact with, the more resistant to said bacteria one becomes. Duh. Did you know that the bacterial cells in and on your body outnumber your human cells? They're a part of how we function and stay healthy. So stop washing your hands so much and throw away any anti-bacterial cleaners you might have around the house.