Smart Guy

A tractor salesman was passing a farm, where the farmer was plowing the field with a bull. He goes over and offers to sell the farmer a tractor to plow with.
The farmer tells him "I don't need a tractor, I have three new ones at the barn"
Well if you have three new tractors at the barn, why are you plowing this field with that bull, asked the salesman ?
The farmer replied, "This is part of the bulls continuing education, I am teaching him that there is more to farming than fucking and tearing down fences.