A small boy was walking along a beach at low tide, where countless
thousands of small sea creatures, having been washed up, were stranded
and doomed to perish. A man watched as the boy picked up individual
creatures and took them back into the water.
"I can see you're being very kind," said the watching man, "But there
must be a million of them; it can't possibly make any difference."
Returning from the water's edge, the boy said, "It will for that one."