The story goes that young girl (or boy in some tellings of the very old story)
is walking along the beach when she sees hundreds of starfish washed up on the shore.

 

She feels sorry for them– because she realizes that many of them are still alive.
She begins chucking them back out to sea so they won’t die on the beach.

 

An older man comes along and asks her,
“Why are you throwing those starfish back out into the sea?
Don’t you know that you can’t possibly save all these starfish!
There are miles and miles of shoreline, and the sun is already up.
What difference can you make when there are so many to be saved?”

After thinking about it for a moment, and throwing one more starfish back out into the water, the girl replies:

“I made a difference to that one!”

Story also called the Star-Thrower.