Little Boy #1 (solemnly): Mama, I dropped my waffle, but I did NOT eat it off the floor.
Me: Oh, good!
Little Boy #1 (proudly): See! I catched it with my feet!
Me: Go wash your face with a wet paper towel in the bathroom, please.
Little Boy #2 goes into the bathroom, gets a paper towel and starts to wipe his face.
Me: No, you have to get it wet first or it won't clean anything off your face.
Little Boy #2 wipes snotty nose and holds up paper towel triumphantly: See! It's wet!
*groan* Well, germs build immunity, right?