There is a distinct difference between "the Flu" and a cold. When one cops the real flu, they are bed ridden and basically incapacitated. Colds make one just plain miserable but still able to do stuff to some extent. I dont think I have ever had a Flu, had some pretty miserable colds and that sort of thing though. Mind you now days people's habits can leave them open to all sorts of bugs, you only have to go into a public toilet and watch the amount of people that dont wash their hands properly. Even money, keypads on teller machines are contaminated, so the idea is to keep ones hands as clean as possible and out of the mouth.
Just my 2 cents worth