Mr. Smith was walking through a valley when he suddenly noticed that his feet were getting wet. It then dawned upon him that this little valley of his was actually an arm of the sea and that high tide was coming in.
He stood still and looked around to find someone with a boat. So long as he kept waiting for a boat to come and rescue him, he kept right on standing where he was. But no boat came.
So he gave up on that idea and then began to wish that the tide would not rise any higher. But when the water reached his chin, he also gave up that idea and began to swim.
Only then did he realize that he himself was a boat.