The teacher knew little Johnny always brought two sandwiches to school for his lunch. One day the teacher discovered that little Billy had forgotten his lunch box and had nothing to eat. The teacher diplomatically approached little Johnny and said "Gosh Johnny, did you know Billy forgot his lunch and has nothing to eat? Since you have two sandwiches, how about sharing your extra sandwich with Billy today?" To which Johnny replied "You know, normally I would be glad to, it's just that I'm eating my EXTRA sandwich first today!"