As a bi-ped still learning to use his opposable digits, I occasionally drop things on the floor.  What happens next depends entirely on the type of floor and the object dropped.  If I drop something on the floor of my house, I'll pick it up, wipe the cat hair off of it, and use it again without thinking, whether it's a fork, a pen, or a piece of food.  On a scale from 1 to gross, I'm on the gross end.  But look at me; I'm 26 years old, in the best shape and health of my life.  Apparently my intake of foreign bacteria and germs isn't too much to bring about my downfall.  However, there are instances where I won't even consider reusing an object that fell on the floor.  One such place is the bathroom at work.  Not that it's especially dirty or gross, but it's a public mens bathroom.  It's exactly as clean as you'd expect.  I don't bring food in the bathroom (as no one in their right mind should), so that's not a problem.  But I often drop a clean paper towel on the ground after I wash my hands.  There's a split second decision that happens in my mind, but it's always the same:  "Eh, it's still goo--No.  It's the bathroom."  I don't care how clean that paper towel is before it touches the ground or how many seconds of the 5-second rule have passed.  Objects dropped on the bathroom floor can never be used again. #entertainment