If you give your players a quest to accomplish, it's too easy to spell out all the requirements explicitly. Instead, try just dropping vague hints as to what needs to be done.

For example, they might know they need to retrieve a "blue rabbit", but they have no idea what sort of rabbit or why it's blue, or if it's a specific legendary blue rabbit, or just any old blue rabbit.

They might not even know that "rabbit" is a corruption of a word in an ancient language, "rebett", which actually means "gem", and not rabbit at all...

Transcript

Luke: Meekness?
{flashback:}
Palpatine: Slowly, then, your life support surrenders. Grasp it, sense it, helpless and defenceless.
Darth Vader: My lord.
Luke: Then... the opposite of totalitarianism... help me out, Yoda.
Yoda's voice: Socialism, it was.
Chewbacca: Socialism? Really??
Luke: Hey, I was pretty close!
Yoda's voice: Close enough, yes. The correct sentiments, you expressed.
{flashback:}
Luke: Join me and overthrow the Emperor! We can bring peace and equality and freedom to the Galaxy.
Darth Vader: Peace... to the Galaxy. Democracy. Shared prosperity. It does sound... welcome. But...
Luke: Then, uh, the opposite of power.
Darth Vader: Sacrifice. Like when you were willing to die to save me.
{flashback}
Luke: Stop! Or I'll Force Transcend myself! If I can't use this body, you can't either!
Luke: Whoa...
Yoda's voice: Just as Padmé sacrificed herself to save you.
{flashback:}
Palpatine: Hey Siri; Order 66!
[SFX]: KRZZRKZZZT!
Darth Vader: Aaargghh!!
Luke: So we both just need the last step! Um.
Yoda's voice: Achieved it yet...
Yoda's voice: you have not.