Making lists can be a vital part of enjoying a game. Lists of equipment, lists of desired magic items, lists of NPCs you've offended and who will probably try to kill you next time you meet them...
A cool character quirk can be the propensity to constantly make lists of things. Most often this will involve listing "things that can go wrong" whenever another character proposes a course of action.
Han: All right. Here's the plan. We attack the base in a full frontal assault.
Paploo: Um... We might have a better idea.
Han: What could be better than that?
Wicket: We know a back door. It's much more lightly guarded.
Han: Why would we want to go there?
Wicket: It's... much more lightly guarded?
Han: Sounds dangerous. Let me list the benefits of a frontal assault:
Han: 1. So much more awesome.
Han: 2. They'll never expect it.
Leia: Is that it?
R2-D2: 3. Profit!