Many NPCs do nothing but react to the actions of PCs. It's a good idea to have an NPC drive the conversation occasionally. This is likely to happen if the heroes meet the king, or some sort of authorities, but try doing it with a relative nobody, who just happens to be pushy and asks a lot of questions - but who the heroes have to deal with if they want to make progress, so they can't just ignore them.
Transcript
[SFX]: step
[SFX]: step
[SFX]: poke poke
{Wicket pokes Leia with spear, Leia stirs}
Wicket: Excuse me, have you accepted the word and truth of our Lord and Franchiser, Nute Gunray?
Leia: Huh, what? Uh, no...
Wicket: Won't you just invest a moment of your time to hear the truth?
Leia: Oh good lord...
Wicket: Well yes, but more like a mutually beneficial lord. Do you have any food?
Leia: Uh, sure. Here you go. {Wicket takes the food}
Wicket: No no no no... You had a supply, and I expressed a demand. What does this lead to?
Leia: Uh...
Wicket: {eating the food} Let me tell you the parable of the free lunch.
Leia: What? You're making that up. There's no such thing.
Wicket: Very astute! I think I can get you in at level two.