John was waiting to cross the street when a blind man approached with his guide-dog. The traffic sign turned green and instead of helping its master to cross, the dog raised its rear leg and peed on the shoes of the blind man.
Observing that, the blind man reached into his pocket and offered the dog a cookie.
John told the blind man in amazement, "If it is my dog I'd have kicked its butt!". The blind man calmly replied, "I'm going to. But I need to find its head first".