Milk and eggs
This is a story which is perfectly logical to all males:
A wife asks her husband, "Could you please go shopping for me and buy one carton of milk, and if they have eggs, get 6."
A short time later the husband comes back with 6 cartons of milk.
The wife asks him, "Why did you buy 6 cartons of milk?"
He replied, "They had eggs."
(I'm sure you're going back to read this again as this is the root of most marriage problems!!)