True Scenario:
Shelf stacker in supermarket is bursting for a , so runs the loo....finishes, and as per health & safety, washed his hands throughly. He then exits by grabbing the door handle, and in the process transfers hundreds of other peoples germs and pee onto his hands.
He then returns to stacking the cakes & bread.
You come in, buy a box of cakes, touching the outer box. Get back to your car starving, open the cake box and grab one.....guess what you have just transferred onto your food?
....and yet this has been going on for centuries, and I don't hear of folk dropping dead, as it is these things that build up our immune system. If everything was sterile, we would drop dead from the first germ we come across.