Why folks sometimes don't do things that seem logical

While walking along a beach, an elderly gentleman saw someone in the distance leaning down, picking something up and throwing it into the ocean.
As he got closer, he noticed that the figure was that of a young man, picking up starfish one by one and tossing each one gently back into the water.
He came closer still and called out, "Good morning! May I ask what it is that you are doing?"

The young man paused, looked up, and replied, "Throwing starfish into the ocean."
The old man smiled, and said, "I must ask, then, why are you throwing starfish into the ocean?"
To this, the young man replied, "The sun is up and the tide is going out. If I don't throw them in, they'll die."

Upon hearing this, the elderly observer commented, "But, young man, do you not realize that there are miles and miles of beach and there are starfish all along every mile? You can't possibly make a difference!"

The young man listened politely. Then he bent down, picked up another starfish, threw it into the back into the ocean past the breaking waves and said, "It made a difference for that one."
-Unk.