Do you wash your hands EVERY time you use a public restroom?
Perhaps you wash your hands religiously after using the restroom at a store or restaurant, but not so much at work. Who cares, you know all those people in the office and they're like family, right? You can let the hand-washing slide there. Ew! Family members and those donut-eating co-workers have germs too.
Just how many people skip washing their hands at public restrooms and go ahead and spread the germs?