I think, I had first read this story in Shiv Khera's famous book: 'You Can Win'. The story goes like this:
A man bought a 'special dog'. This dog possessed unique skill of running over the water. The man would take the dog along every time he went for hunting. When a bird was shot dead, the dog would rush to the spot, with lightening speed, to fetch the prey to his master. Undoubtedly, he was skillful even to fetch it when the bird had fallen in a lake or a river. The dog was special. He could run over the deep water! The man was very proud and happy too.
One day, this man wanted to show to one of his friends, what a special dog he possessed. So, he took this friend along for hunting. When he shot down a bird, the amazing dog sprung into action, and, in no time, was back with the bird to his beloved master.
"Did you see?" the man asked with pride.
"Yes," the friend replied.
"Can you tell me, why is my dog so 'different'?" the man wanted to be assured.
"Because, your dog can not swim, unlike other dogs." the reply was instant!
I love this story. Specially when I silently 'suffer' from persons even after reaching out to them 'self-lessly'.
"Self-lessly?" they would react, "No way."
"In life, suffering is optional," I have been told, "even though pain is inevitable."