An old sailor repeatedly got lost at sea, so his friends gave him a compass and urged him to use it. The next time he went out in his boat, he followed their advice and took the compass with him. But as usual he became hopelessly confused and was unable to find land.
Finally he was rescued by his friends. Disgusted and impatient with him, they asked, "Why didn't you use that compass we gave you? You could have saved us a lot of trouble!"
The sailor responded, "I didn't dare to! I wanted to go north, but as hard as I tried to make the needle aim in that direction, it just kept on pointing southeast."
That old sailor was so certain he knew which was north that he stubbornly tired to force his own personal persuasion on his compass. Unable to do so, he tossed it aside as worthless and failed to benefit from the guidance it offered.