And another quote

"Johnnie."

"Yes, teacher."

"If there are twenty sheep in a field, and one gets out through a hole in the fence, how many sheep are left in the field?"

"None, teacher."

"Johnnie, there are still nineteen sheep left in the field. Obviously you don't know arithmetic."

"Sorry, teacher, but I do know arithmetic. Obviously you don't know sheep."

From http://www.backwoodshome.com/