The story of the youth who went forth to learn what fear was

Here goes a story about two brothers. The one was hard-working and smart while the other one was quite the opposite. He was so stupid that he even did not know what it meant to get scared or be afraid of something. A sexton offered to help him and tried to give the young boy the creeps. But it went all wrong. The sexton ended up with a broken leg. What happened? Will the young boy get himself out of the mess? What if you knew that one of the two brothers in the story was going to become king? Who would you bet on?