An old man walking along a beach one day, notices a youth picking up starfish
and flinging them into the sea. The old man asks, "Why are you doing this?"
The young man responds, "If left on the beach 'til the noonday sun, they will
die." "But," protests the old man, "the beach goes on for miles and there are
millions of starfish. How can your effort make any difference?" Looking at the
starfish in his hand, the young man replies, "It makes a very real difference
to this one." 
- Source Unknown