A crowd has gathered near Niagara Falls where a man has strung a rope across the falls and is standing on the edge of the falls with a wheelbarrow. He tells the crowd he is prepared to push the wheelbarrow along the rope and walk across Niagara Falls. In order to get the crowd stirred up, the man asks, "Who here believes I can cross the falls, pushing this wheelbarrow across this rope?" Some of the people raise their hands.
The man says, "Well, if you don't really believe I can do it, there's no point in continuing." More hands go up, and some of the people shout, "Yes, we believe you can do it!" The man says, "Are you sure you believe it? After all, I'm risking my life here." The people shout their encouragement even louder, and one man near the front jumps up and down, shouting, "I believe! I believe!"
The man addresses this enthusiastic believer: "Really, you believe I can do this?" The other man replies, "Yes, yes, I believe!" The first man nods his head and says, "OK, then get in the wheelbarrow."