A lot of things depend on how you look at them, especially things like human motivations.

So why not set up a quest that can only be completed by the correct motivations or emotions, rather than by simply finding the right object or killing the right monster? There are elements of this in fairy tales - needing to to break the curse by finding true love - which leave room open for creative interpretation (see Frozen for a good example). There's no reason you can't borrow such elements and insert them into a more serious or gritty campaign.

Imagine how different the story would have been if Dorothy could never return home until she accepted that she would have to live in Oz forever. Or if Frodo couldn't destroy the Ring until Sam let him throw himself into the fires of Mount Doom with it (and he skipped third dessert).

Transcript

Luke: The Path to the Light Side is easy! You just need to go through the... 14 steps.
Darth Vader: That seems like a lot for someone who should be dead already.
Luke: No! No! You've probably already done some!
Luke: Empathy is the first one... You had empathy for Anakin!
{flashback:}
Palpatine: Anakin was a hero of the Republic; but sadly he was too far gone.
Darth Vader: He's d-d-... dead?
Luke: And then calm! Vader was always pretty calm.
{flashback:}
Darth Vader: {to Daine Jir} Yes.
Luke: Then introspection. Did you ever do that?
Darth Vader: Hmmm.
{flashback:}
Darth Vader: You and I are united by this tragedy. Weep not, for our sins shall be erased.
Luke: Tolerance... Well, you did that warning choke thing on the original Peace Moon. I know from our psychic link. Maybe that counts?
{flashback:}
Clone Trooper 1: {softly} Did you see that memo from Lord Vader? We get one warning choke now.
Clone Trooper 2: {softly} Yeah, I'm going to use mine to tell a Rebel I love him.
Chewbacca: If that's tolerance, then skipping third dessert is restraint.
R2-D2: It is for a Hobbit.