A man was driving down a country road when his car stalled inexplicably. He got out and lifted the bonnet to see if he could find out what had happened.
A brown and white cow slowly lumbered over to the car and stuck her head under the bonnet beside the man.
After a moment the cow looked at the man and said, "Looks like the cylinder head gasket to me!" Then she just turned and walked away.
Amazed, the man walked over to the farmhouse where he met a farmer.
"I say, is that your cow in the field?" he asked.
The farmer replied, "The brown and white one? Yes, that's old Mary."
The man said, "Well my car's broken down, and she just said, 'Looks like the cylinder head gasket to me!"
The farmer shook his head and said, "Don't mind old Mary, she doesn't know anything about cars!"