Five stars for Puddleglum, who is in my top five literary heroes of all time. Here's how he works: 
 1. What is my duty? 
 2. What are the worst things that could happen if I fulfill my duty? 
 3. Do my duty anyway 
 4. Genuine surprise that none of those terrible things happened. 
 5. Assume that terrible things will happen the next time I do my duty 
 6. Repeat 
 Result: Puddleglum is immune to despair. 
 I'm not saying the story is repetitive or predictable; I just like having a genuine hero in my story. And I love quoting his polite rebuttal to the witch.