I remember when my eldest girl Christie was about 3 or 4, and we went to an Italian Restaurant. She was always very well behaved, and always full of manners. When our entree was served (it was Bolognese I think), the waiter asked my wife if she'd like Mozzarella cheese sprinkled on it, and she did.
Next thing, Christie pipes up in her squealy voice "Mum, that smells like vomit"
Well, it brought the house down, everyone burst out laughing.