A friend of ours was walking down a deserted Mexican beach at sunset. As he walked along, he began to see another man in the distance. As he grew nearer, he noticed that the local native kept leaning down, picking something up, and throwing it out into the water. Time and again, he kept hurling something out into the ocean.
As our friend approached even closer, he noticed that the man was picking up starfish that had washed up on the beach and, one at a time, was throwing them back into the water.
Our friend was puzzled. He approached the man and said, "Good evening, friend. I was wondering what you are doing?"
"I'm throwing these starfish back into the ocean. You see, it is low tide right now, and all of these starfish have washed up onto the shore. If I don't throw them back into the sea, they'll die from lack of oxygen."
"I understand," my friend replied, "but there must be thousands of starfish on this beach! You can't possibly get to all of them. There are simply too many! And don't you realize this is probably happening on hundreds of beaches all up and down this coast? Can't you see that you can't possibly make a difference?"
The local native smiled, bent down, and picked up yet another starfish and, as he threw it back into the sea, replied, "Made a difference to THAT one!"